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A248744
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Number of different ways one can attack all squares on an n X n chessboard with n rooks.
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6
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1, 1, 6, 48, 488, 6130, 92592, 1642046, 33514112, 774478098, 19996371200, 570583424422, 17831721894912, 605743986163706, 22223926472824832, 875786473087350750, 36893467224629215232, 1654480168085245432354, 78692809748219369422848, 3956839189675526769415958
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OFFSET
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0,3
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COMMENTS
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Number of minimum (and minimal) dominating sets in the n X n rook graph. - Eric W. Weisstein, Jun 20 2017 and Aug 02 2017
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REFERENCES
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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
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LINKS
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FORMULA
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a(n) = 2*n^n - n!.
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MAPLE
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MATHEMATICA
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Table[2 n^n - n!, {n, 20}]
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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