The Math Blog: The Math Blog: Octagonal Numbers

Friday, March 15, 2013

Headline: $n^2 + 4\sum_{k = 1}^{n - 1} k = 3n^2-2n$

I might as well say that this blog is currently managed along with some other blogs, which I'll mention later.

Octagonal numbers grow like pentagonal, hexagonal, and heptagonal numbers. The formula for any octagonal number n is:

$O_n = 3n^2-2n$ (credit to Wikipedia)

Bye for now!

MATH NEWS IS NOW BEING AWESOME WITH FEATURED SEQUENCE:

3, 7, 31, 127...

Guess what the sequence is! Answer in the next post.