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%I #16 Mar 19 2023 08:21:38
%S 0,0,0,2080,27768,181032,807040,2817240,8271480,21328048,49692672,
%T 106717680,214322680,406928280,736614528,1279735912,2145244920,
%U 3484996320,5506324480,8487206208,12794341752,18904506760,27429548160,39145417080,55025652088,76279746192
%N Number of ways to place 2 nonattacking kings on an n X n X n X n raumschach board (four-dimensional chessboard).
%H Vincenzo Librandi, <a href="/A194605/b194605.txt">Table of n, a(n) for n = 0..10000</a>
%H <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (9,-36,84,-126,126,-84,36,-9,1).
%F a(n) = (n^8 - (3*n-2)^4) / 2 for n>0.
%F G.f.: 8*x^3*(260+1131*x+750*x^2+335*x^3+75*x^4-30*x^5-x^6)/(1-x)^9. - _Bruno Berselli_, Aug 31 2011
%Y Cf. A061995, A166540.
%Y Cf. A194604 for the general d-dimensional case.
%K nonn,easy
%O 0,4
%A _Andrew Woods_, Aug 30 2011
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