This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A212270 #25 May 22 2021 01:07:58 %S A212270 2,7,43,933,36211,3557711,746156517,363549830913,394677987525997, %T A212270 974602314570939359,5418730454986467701985,68176187476467835406646029, %U A212270 1936241516342334422813929891295,124281423643836238320564876791634465,18018270577720149773239661332878801006033 %N A212270 Number of ways to place k non-attacking wazirs on an n x n cylindrical chessboard, summed over all k >= 0. %C A212270 Wazir is a leaper [0,1]. %H A212270 Vaclav Kotesovec, <a href="/A212270/b212270.txt">Table of n, a(n) for n = 1..32</a> %H A212270 V. Kotesovec, <a href="https://oeis.org/wiki/User:Vaclav_Kotesovec">Non-attacking chess pieces</a>, 6ed, 2013, p.414 %F A212270 Limit n ->infinity (a(n))^(1/n^2) is the hard square entropy constant A085850. %Y A212270 Main diagonal of A286513. %Y A212270 Cf. A006506, A027683, A182407, A212269, A212271. %K A212270 nonn,hard %O A212270 1,1 %A A212270 _Vaclav Kotesovec_, May 12 2012