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 A201511 #26 Apr 16 2024 19:48:16 %S A201511 1,1,2,22,405,10741,368868,15516804,771464278,44218721793, %T A201511 2868879752822,207739939478618,16602826428818482,1451305771147909684, %U A201511 137715836041691050398,14096224186664736126206,1547966111897855935957132,181519663430661533452513680,22636566614411901986006002896 %N A201511 Number of ways to place n nonattacking wazirs on an n X n board. %C A201511 Wazir is a leaper [0,1]. %H A201511 Vaclav Kotesovec, <a href="/A201511/b201511.txt">Table of n, a(n) for n = 0..21</a> (terms a(11)-a(18) computed by Peter Tittmann) %H A201511 V. Kotesovec, <a href="https://oeis.org/wiki/User:Vaclav_Kotesovec">Non-attacking chess pieces</a>, 6ed, 2013, p. 382. %H A201511 Peter Tittmann, <a href="http://www.staff.hs-mittweida.de/~peter/research/grids.html">Polynomials of nxn Grid Graphs</a> [broken link] %F A201511 Asymptotics (Vaclav Kotesovec, Nov 29 2011): a(n) ~ n^(2n)/n!*exp(-5/2). %Y A201511 Cf. A172225, A172226, A172227, A172228, A178409, A201507, A201508, A201510. %Y A201511 Cf. A006506. %Y A201511 Main diagonal of A232833. %K A201511 nonn,nice,hard %O A201511 0,3 %A A201511 _Vaclav Kotesovec_, Dec 02 2011 %E A201511 a(19)-a(20) from _Vaclav Kotesovec_, Aug 30 2016 %E A201511 a(0)=1 prepended by _Alois P. Heinz_, Apr 16 2024