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 A179426 #17 Aug 05 2024 10:20:48
%S A179426 0,0,0,0,0,10596,486668,7063520,55345356,299491100,1263811604,
%T A179426 4455716184,13701863604,37823872044,95648273100,224887404416,
%U A179426 497181121100,1042609380588,2088337713332,4017815773400,7459198321428,13414493857116,23444476061772,39928736913120,66425550447500,108162598959740,172697249542932,270794133842456,417578468928308,634036069773900
%N A179426 Number of ways to place 6 nonattacking kings on an n X n toroidal board.
%H A179426 Vincenzo Librandi, <a href="/A179426/b179426.txt">Table of n, a(n) for n = 1..1000</a>
%H A179426 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 A179426 <a href="/index/Rec#order_13">Index entries for linear recurrences with constant coefficients</a>, signature (13, -78, 286, -715, 1287, -1716, 1716, -1287, 715, -286, 78, -13, 1).
%F A179426 a(n) = 1/720*n^2*(n^10 -135*n^8 +7525*n^6 -217665*n^4 +3289354*n^2 -20949480), n>=7.
%F A179426 G.f.: 4*x^6*(426*x^13 - 4263*x^12 + 22311*x^11 - 82449*x^10 + 220918*x^9 - 391803*x^8 + 369356*x^7 + 10716*x^6 - 382230*x^5 + 163719*x^4 + 387689*x^3 - 390831*x^2 - 87230*x - 2649)/(x-1)^13.
%t A179426 CoefficientList[Series[4 x^5 (426 x^13 - 4263 x^12 + 22311 x^11 - 82449 x^10 + 220918 x^9 - 391803 x^8 + 369356 x^7 + 10716 x^6 - 382230 x^5 + 163719 x^4 + 387689 x^3 - 390831 x^2 - 87230 x - 2649) / (x - 1)^13, {x, 0, 50}], x] (* _Vincenzo Librandi_, Jun 01 2013 *)
%Y A179426 Cf. A172158, A179403, A179404, A179424, A179425.
%K A179426 nonn,easy
%O A179426 1,6
%A A179426 _Vaclav Kotesovec_, Jan 07 2011