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%I #14 Feb 20 2018 14:29:46
%S 0,2,504,10010,78052,368868,1280832,3612344,8774380,19049692,37898664,
%T 70311824,123209012,205885204,330502992,512631720,771833276,
%U 1132294540,1623506488,2280989952,3147068036,4271685188,5713272928,7539662232,9829042572,12670967612
%N Number of ways to place 6 nonattacking wazirs on a 6 X n board.
%C Wazir is a (fairy chess) leaper [0,1].
%H Vincenzo Librandi, <a href="/A172232/b172232.txt">Table of n, a(n) for n = 1..1000</a>
%H 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 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/GridGraph.html">Grid Graph</a>
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Wazir_(chess)">Wazir (chess)</a>
%F 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 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 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 Cf. A172229, A172230, A172231, A061992.
%K nonn,easy
%O 1,2
%A _Vaclav Kotesovec_, Jan 29 2010
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