I tried to break the series into different parts by two different methods   In terms of even and odd (no specific series is obtained in even, only Geometric progression formula can be applied on odd series) In terms that contain powers of $2$ only, terms with $3$ to $1$st power, $3$ to $2$nd power,.. and so on   More specific pattern is obtained in the second method but I can't solve it further.  Help me further with the second method or any other one.  Any method given is appreciated.
I'm in trouble with this homework.  Find the sum of the series $ 1 + \frac12 + \frac13 + \frac14 + \frac16 + \frac18 + \frac19 + \frac1{12} +\cdots$, where the terms are the inverse of the positive integers whose only prime factors are 2 and 3.  Hint: write the series as a product of two geometric series.  Ok, I found some patterns in these numbers, but I can't find the two series.
Travel in schengen countries without carrying passport for non EU citizen Details on how the Yearling badge works Jawa asked me this  and I didn't know the answer. So I present it to the meta SO community:     [To get the Yearling badge] Do you need to earn the 200 rep within that one year or is it enough to get 200 at some point after being a member for a year? And does 'a year' mean the very first 12 months or the last (sliding window of) 12 months?    I would assume that if you hit 200 reputation after you've already been around for a year, then you would get the Yearling badge. But I don't know. I just graduated, and I'm starting a new job soon. My employer has pretty good policy for matching 401(k) contributions, so I want to invest as much as possible, especially during this first year.  My question is: should I invest in a traditional 401(k), a Roth 401(k), or some combination of the two? On the one hand, tax rates may be much higher when I retire, and I might be in a higher tax bracket, so a Roth 401(k) would be good. On the other hand, I might be in a lower tax bracket when I retire, so a traditional 401(k) might be better. It's hard to know where I will stand in 30 years.  Is this the same trade-off as with a traditional / Roth IRA, or is there any other tax difference I should know about? Let $R$ be a commutative ring.  The nilradical $\text{nil}(R)$ is the set of all nilpotent elements, and it is the intersection of all the prime ideals of $R$.  Is the following true in the polynomial ring? $$\text{nil}(R[X])=(\text{nil}(R))[X]$$  Any polynomial in the right hand side has all its coefficients nilpotent in $R$, hence also in $R[X]$, and therefore it is nilpotent in $R[X]$ as the sum of nilpotent elements.  The other inclusion is not clear to me.  Is there a counterexample? What is meant by "obfuscate by pretending"? I came accross the following sentence:  "Politicians obfuscate by pretending that the world would be the same if it weren't for the Cold War."  What is the meaning of obfuscate by pretending and how does it relate to the rest of the sentence?  The way I understood it: politicans are aware that the world would not be the same if it weren't for the Cold War, but are (due to unknown or suspected reasons) not willing to admit this and therefore pretend otherwise. I´d like to enable the ssh root access on Ubuntu 14.04. Editing the /etc/ssh_config (PermitRootLogin yes) didn't affect anything. how long to cook a turkey per pound We have officially discontinued the Amazon book affiliate remnant ads, since despite our best efforts they don't perform well for our audience and cannot be made to perform well.  We've often wondered,   I'm thinking this isn't a problem; it has gotten lots of support historically. So we're going to go ahead and do it, so the company Amazon account is still getting some use, and we benefit a little.   To be clear: from this point on, all Amazon links posted on all sites will automatically be rewritten to add our affiliate link. We have a clever affiliate redirect that geolocates the IP address and redirects to the appropriate regional Amazon store (amazon.uk, amazon.ca, et cetera).  If you have any feedback on this, or suggestions, as they say &hellip; speak now or forever hold your peace! Add self-answer delay for all users TL;DR:  I believe there are still some issues with self-answers, particularly near-immediate self-answers, which are not addressed by the current system.  This could be remedied by imposing an automated restriction on how soon self-answers will be displayed in the thread.  Allow users to submit self-answers at any time, but do not display them until certain reasonable conditions (a relatively short timeout, or the posting of a competing answer) are met.    History  This thread covers a good deal of the concerns surrounding self-answers, and some mechanisms in place to prevent "bad" self-answers from new users and other abuse of the self-answer system.    As I understand it, the following restrictions apply:   Users with &lt;100 rep cannot self-answer within 8 hours of posting a question. Self-answers cannot be accepted within 48 hours of posting. Self-answers do not provide rep from being accepted. Accepted self-answers are not pinned to the top of the thread.   Problem  This does a good job of preventing users from posting answers which should probably be comments (or not posted at all), allows superior answers to rise above accepted self-answers, and prevents some other abuses of the system.  However, there is a less tangible element of self-answers which this does not address:    Self answers are a disincentive to other users who may otherwise be willing to post more accurate, detailed material stemming from broader or deeper knowledge and/or experience than the asker has.  When someone posts an answer to their own question, it presumably means that the problem which spawned the question is solved to their satisfaction.  This is fine for the purposes of sharing information with the community, but it deters others from providing solutions to the question which may be more complete or accurate since there is not so much likelihood that the self-answerer will accept a competing answer.  Worse, in the case of near-immediate self-answers, this can remove the incentive for other users to gain reputation via up-votes because the asker has an unfair head-start.  Unless everyone is required to view new answers to questions where they have already voted on an answer, most people probably vote on a good answer and never look at the question again.  This can put (potentially) better answers at a disadvantage even when the head-start is within an hour.  Suggested Solution  Add a delay to the posting of self-answers.  The delay should be the least of these:   Until a competing answer has been posted. A reasonable amount of time to allow competing answerers a chance to post, without preventing self-answers outright.  (Suggestion: 2 hours)   To better facilitate this, and avoid completely turning people off from appropriate self-answering, I suggest the delay be handled through automation more than user limitation.  That is, the user should be allowed to submit the self-answer at any time.  But the answer will not actually be displayed to other users until one of the above conditions have been met.  This could also be applied to the existing 8-hour delay for low-rep users.  Example:  T:0 - A user finishes resolving a tough problem, just before he would have gone to SE for assistance, and decides to share his new-found knowledge with the community.  He posts a question describing his problem.  T:5 minutes - The user then posts a self-answer.  There has not yet been another answer posted to the thread.  The user is given a notice describing the restrictions in place regarding self-answers, and the answer is submitted into the database but not displayed to other users.  (Similar to how suggested edits are only displayed to the user suggesting them, until they are approved.)  T:1 hour, 15 minutes - Another user sees the unanswered question, and posts their answer.  Their answer is displayed immediately, and the self-answer is now also displayed.  T:2 hours - Had the second answer not been posted, the self-answer would automatically be displayed after this point. I have installed an Ubuntu server on a VMWare workstation with a space of 20GB storage as seen below;    After the installation I've attached another 40GB worth storage to the existing Ubuntu server installation (seen below);    Now I want to add this 40GB to my / (root) directory or to /var/ directory but my df -h result shows;  root@Userver:~# df -h Filesystem      Size  Used Avail Use% Mounted on /dev/sda1        18G  900M   16G   6% / udev            990M  4.0K  990M   1% /dev tmpfs           400M  308K  399M   1% /run none            5.0M     0  5.0M   0% /run/lock none            999M     0  999M   0% /run/shm none            100M     0  100M   0% /run/user root@Userver:~#   What should I do now? Further, I have only ssh access to the server. What are the TeX definitions for the hyphen and dashes -, --, and ---? I've tried latexdef which does not handle --- as the operand. And \texemdash is defined as a character. So that leaves me once again leaning on the collective wisdom of the group :) Why do extract recipes call for a late addition of the bulk of the extract? My recipe calls for a pound of DME at the beginning of the boil and 6 pounds at 15 minutes to go.  What's the point of that? How do you redirect to a page using the POST verb? When you call RedirectToAction within a controller, it automatically redirects using an HTTP GET.  How do I explicitly tell it to use an HTTP POST?  I have an action that accepts both GET and POST requests, and I want to be able to RedirectToAction using  POST and send it some values.  Like this:  this.RedirectToAction(     "actionname",     new RouteValueDictionary(new { someValue = 2, anotherValue = "text" }) );   I want the someValue and anotherValue values to be sent using an HTTP POST instead of a GET. Does anyone know how to do this? How do I easily rename multiple files using command line? Since canonical is  Ubuntu One, what are the possible alternatives?  I currently use Ubuntu One as a backup service for my Documents folder and various other folders I deem important. Of course I have backups on an external hard drive as well, but nevertheless, I find Ubuntu One to be very useful. What I'm especially looking for is a cloud service that does not need a special folder (such as a dropbox or google drive folder); something that is able to integrate into my own file system and syncs just any folder I want to.   I am aware that this question is rather subjective, but I do guess many people who have used Ubuntu One are now in the dark. help you learn vs. help you to learn Source:  by Douglas Crockford (2008) Example:  My goal here is to help you to learn to think in JavaScript. I will show you the components of the language and start you on the process of discovering the ways those components can be put together.  Although it is usually the case that you mostly hear people say something like &quot;this will help you become a better person&quot;, is there any particular reason as to why he chose not to leave out the to and say help you to learn instead? If you've got something interesting to say, could you please elaborate on it as well? I would very much like to receive some coherent explanation and get this thing finally straight. The only time I know of, though, that you would use the to is when you say it like this:  It helps a lot to think of the rather difficult concept of classes used in modern software development as mere blueprints that architects and builders use to build houses. In life, it really helps to know your times tables by heart because not all the time do you have a calculator on you.  Because the aspect of the verb &quot;help&quot; is a little bit different here. But in all other cases, help do or help you do something is by far more common. Electrostatic charge leakage What are the ways electrostatic charged objects leak charge in humid conditions?  Can airborne particles pick up charge by contact, then be repelled hence removing charge? If so would it be a significant factor? One of the most common security best practices these days seems to be . I've never really found a good explanation for that, but I'm assuming it's to minimize the risk of a  malicious or infected script within the webroot from reading the database password.  But, you still have to let WordPress access it, so you need to expand open_basedir to include the directory above the document root. Doesn't that just defeat the entire purpose, and also potentially expose server logs, backups, etc to attackers?  Or is the technique only trying to prevent a situation where wp-config.php would be shown as plain-text to anyone requesting http://example.com/wp-config.php, instead of being parsed by the PHP engine? That seems like a very rare occurance, and it wouldn't outweigh the downsides of exposing logs/backups/etc to HTTP requests.  Maybe it's possible to move it outside the document root in some hosting setups without exposing other files, but not in other setups?    Conclusion:  After a lot of back-and-forth on this issue, two answers have emerged that I think should be considered the authoritative ones. Aaron Adams makes a good case in  wp-config, and chrisguitarguymakes a good . Those are the two answers you should read if you're new to the thread and don't want to read the entire thing. The other answers are either redundant or inaccurate. How to change the size of desktop icons? I tried gconf-editor as given at  .  I am not getting the option for changing size at app &gt; nautilus &gt; icon_view.  I am using Ubuntu 11.10. Kindly help me in changing default icon size.   I want to make them small. When I receive a message on an SE post, I get a notification like this:    If I double tap this notification, the SE application opens, but my feed is empty approximately half the time. It looks like this:    If I refresh the feed (slide from the top), the feed does refresh and shows the new notification.   The notification, above, leads to  comment.  I haven't figured out the pattern yet, but this occurs roughly half the time I open a notification. It's occurred for chat messages, comments and answers - but not consistently. I have received notifications for the same post (for example, the two comments after the one linked above) that do not show an empty feed. But, a chat message barely 10 minutes later will show the empty feed again.  I am utilizing the beta app - version 1.0.72 on Android 5.0.1.