The sequence 1, 2, 6, 13, 23, 36..., what is the 30th item of this sequence.
数列1、2、6、13、23、36…，这个数列的第30项是多少．
<gadget id="calculator">29 * 3</gadget>
<output>87</output>

<gadget id="calculator">87 - 2</gadget>
<output>85</output>

<gadget id="calculator">1 + 85</gadget>
<output>86</output>

<gadget id="calculator">29 / 2</gadget>
<output>29/2 = around 14.5</output>

<gadget id="calculator">86 * (29/2)</gadget>
<output>1_247</output>

<gadget id="calculator">1 + 1_247</gadget>
<output>1_248</output>

<result>1_248</result>