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 A177758 #15 Aug 21 2024 10:51:45
%S A177758 0,0,0,0,120,6912,52920,466944,1905120,8647680,25613280,81838080,
%T A177758 198764280,510478080,1082161080,2393997312,4594961280,9120190464,
%U A177758 16225246080,29656350720,49689816120,85128088320,135870624120
%N A177758 Number of ways to place 5 nonattacking bishops on an n X n toroidal board.
%H A177758 Vincenzo Librandi, <a href="/A177758/b177758.txt">Table of n, a(n) for n = 1..1000</a>
%H A177758 V. Kotesovec, <a href="https://oeis.org/wiki/User:Vaclav_Kotesovec">Non-attacking chess pieces</a>, 6ed, 2013
%H A177758 <a href="/index/Rec#order_20">Index entries for linear recurrences with constant coefficients</a>, signature (2, 8, -18, -27, 72, 48, -168, -42, 252, 0, -252, 42, 168, -48, -72, 27, 18, -8, -2, 1).
%F A177758 Explicit formula: 1/240*(n-4)^2*(n-2)^2*n^2*(2n^4 -16n^3 +54n^2 -108n+153 +(10n^2 -60n +135)*(-1)^n).
%F A177758 G.f.: -24x^5*(5x^14 +406x^13 +1333x^12 +14880x^11 +24307x^10 +97498x^9 +95187x^8 +175328x^7 +100307x^6 +93018x^5 +28147x^4 +12832x^3 +1589x^2 +278x+5)/((x-1)^11*(x+1)^9).
%t A177758 CoefficientList[Series[- 24 x^4 (5 x^14 + 406 x^13 + 1333 x^12 + 14880 x^11 + 24307 x^10 + 97498 x^9 + 95187 x^8 + 175328 x^7 + 100307 x^6 + 93018 x^5 + 28147 x^4 + 12832 x^3 + 1589 x^2 + 278 x + 5) / ((x - 1)^11 (x + 1)^9), {x, 0, 50}], x] (* _Vincenzo Librandi_, May 31 2013 *)
%Y A177758 Cf. A172129, A177755, A177756, A177757.
%K A177758 nonn,easy
%O A177758 1,5
%A A177758 _Vaclav Kotesovec_, May 13 2010