@Jonathan I see now. If you look on my comment, I misread yours and thought they were both 2k+1. My mistake.

]]>And Harry, 2k+1 and 2k-1 are consecutive odd integers. Their squares are 4k^2 + 4k – 1 and 4k^2 – 4k – 1, and the difference of those squares is 8k. ]]>

As you noted, some of the problems are very boring, so why would I spend my time preparing for something that bores me? I would be interested to hear any reasons for competing in these math competitions besides, perhaps, to get to compete in the higher level ones.

Also, @Jonathan, minor typo. (2k+1)^2 – (2k+1)^2 is always zero. It should be (2k+1)^2 – (2m+1)^2, or some other variable.

]]>I like, btw, (2k+1)^2 – (2k-1)^2

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