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 A172214 #17 Feb 18 2018 15:01:23
%S A172214 1,28,259,1968,9386,30842,82738,192336,400277,763984,1360797,2291056,
%T A172214 3681226,5687022,8496534,12333352,17459691,24179516,32841667,43842984,
%U A172214 57631432,74709226,95635956,121031712,151580209
%N A172214 Number of ways to place 5 nonattacking knights on a 5 X n board.
%H A172214 Vincenzo Librandi, <a href="/A172214/b172214.txt">Table of n, a(n) for n = 1..1000</a>
%H A172214 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>
%F A172214 a(n) = (625n^5-8250n^4+57235n^3-242778n^2+608440n-705984)/24, n>=8.
%F A172214 G.f.: x * (42*x^12 -52*x^11 -268*x^10 +884*x^9 -268*x^8 -1188*x^7 +2834*x^6 -720*x^5 +918*x^4 +814*x^3 +106*x^2 +22*x +1) / (x-1)^6. - _Vaclav Kotesovec_, Mar 25 2010
%t A172214 CoefficientList[Series[(42 x^12 - 52 x^11 - 268 x^10 + 884 x^9 - 268 x^8 - 1188 x^7 + 2834 x^6 - 720 x^5 + 918 x^4 + 814 x^3 + 106 x^2 + 22 x + 1) / (x - 1)^6, {x, 0, 50}], x] (* _Vincenzo Librandi_, May 27 2013 *)
%Y A172214 Cf. A172136, A061991, A172212, A172213.
%K A172214 nonn,easy
%O A172214 1,2
%A A172214 _Vaclav Kotesovec_, Jan 29 2010