title: construct large square using smaller squares
body: <p>I have a large square of edge <code>N</code>. I want to calculate the number of small squares required to construct this large square using smaller squares with edge values from <code>1</code> to <code>N-1</code>. I have unlimited number of such small squares.The only restriction is that I have to use the <code>minimum</code> number of smaller squares.For example,if N=3, I can construct this square using 5 squares of size <code>1</code> and 1 square of size <code>2</code>. How can I solve this problem for any given value of <code>N</code>?</p>