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%I #68 Nov 30 2017 19:12:12
%S 1,1,6,48,488,6130,92592,1642046,33514112,774478098,19996371200,
%T 570583424422,17831721894912,605743986163706,22223926472824832,
%U 875786473087350750,36893467224629215232,1654480168085245432354,78692809748219369422848,3956839189675526769415958
%N Number of different ways one can attack all squares on an n X n chessboard with n rooks.
%C Number of minimum (and minimal) dominating sets in the n X n rook graph. - _Eric W. Weisstein_, Jun 20 2017 and Aug 02 2017
%D A. M. Yaglom and I. M. Yaglom, Challenging Mathematical Problems with Elementary Solutions, Vol. 1: Combinatorial Analysis and Probability Theory, Dover Publications, 1987, p. 77
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/MinimalDominatingSet.html">Minimal Dominating Set</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/MinimumDominatingSet.html">Minimum Dominating Set</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/RookGraph.html">Rook Graph</a>
%F a(n) = 2*n^n - n!.
%p A248744:=n->2*n^n-n!: seq(A248744(n), n=0..25); # _Wesley Ivan Hurt_, Nov 30 2017
%t Table[2 n^n - n!, {n, 20}]
%Y Main diagonal of A290632.
%Y Cf. A000142, A000312.
%K nonn
%O 0,3
%A _Stephen Penrice_, Apr 09 2017
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