Talk:Centered pentagonal number

I'm afraid the formula is not correct; it should read

$P_{n}={{5n^{2}+5n+2} \over 2},n\geq 1$

See also the Mathworld article to which you link at the page bottom. — Preceding unsigned comment added by 91.217.55.78 (talk) 10:19, 14 February 2018 (UTC)