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 A172232 #15 Feb 16 2025 08:33:11 %S A172232 0,2,504,10010,78052,368868,1280832,3612344,8774380,19049692,37898664, %T A172232 70311824,123209012,205885204,330502992,512631720,771833276, %U A172232 1132294540,1623506488,2280989952,3147068036,4271685188,5713272928,7539662232,9829042572,12670967612 %N A172232 Number of ways to place 6 nonattacking wazirs on a 6 X n board. %C A172232 Wazir is a (fairy chess) leaper [0,1]. %H A172232 Vincenzo Librandi, <a href="/A172232/b172232.txt">Table of n, a(n) for n = 1..1000</a> %H A172232 V. Kotesovec, <a href="https://oeis.org/wiki/User:Vaclav_Kotesovec">Number of ways of placing non-attacking queens and kings on boards of various sizes</a> %H A172232 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/GridGraph.html">Grid Graph</a> %H A172232 Wikipedia, <a href="https://en.wikipedia.org/wiki/Wazir_(chess)">Wazir (chess)</a> %F A172232 a(n) = 2*(486*n^6 -5670*n^5 +30240*n^4 -95230*n^3 +187899*n^2 -220775*n +120540) / 15, n>=5. %F A172232 G.f.: -2*x^2 * (3*x^9 -5*x^8 +100*x^7 +354*x^6 +2548*x^5 +7572*x^4 +9248*x^3 +3262*x^2 +245*x +1) / (x-1)^7. - _Vaclav Kotesovec_, Mar 25 2010 %t A172232 CoefficientList[Series[- 2 x (3 x^9 - 5 x^8 + 100 x^7 + 354 x^6 + 2548 x^5 + 7572 x^4 + 9248 x^3 + 3262 x^2 + 245 x + 1) / (x - 1)^7, {x, 0, 50}], x] (* _Vincenzo Librandi_, May 28 2013 *) %Y A172232 Cf. A172229, A172230, A172231, A061992. %K A172232 nonn,easy %O A172232 1,2 %A A172232 _Vaclav Kotesovec_, Jan 29 2010