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A186639
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a(n) = n!/2-(-2)^(n-2)*(n-2).
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0
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1, 0, 1, 5, 4, 84, 296, 2680, 19776, 182336, 1812352, 19963008, 239490560, 3113532928, 43589096448, 653837290496, 10461394714624, 177843714539520, 3201186851815424, 60822550206644224, 1216451004083601408, 25545471085864681472, 562000363888782868480, 12926008369442532360192, 310224200866619627405312, 7755605021665493184937984
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OFFSET
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0,4
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COMMENTS
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"Number of positive terms in the ordinary development of a determinant having negative elements in the diagonal and positive elements elsewhere." [Muir]
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REFERENCES
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T. Muir, A Treatise on the Theory of Determinants. Dover, NY, 1960, Sect. 132, p. 115.
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LINKS
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FORMULA
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MAPLE
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f:=n->n!/2-(-2)^(n-2)*(n-2); [seq(f(n), n=0..40)];
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MATHEMATICA
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Table[n!/2 - (-2)^(n - 2)*(n - 2), {n, 0, 25}] (* Wesley Ivan Hurt, Aug 17 2016 *)
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PROG
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(Magma) [Factorial(n)/2 - (-2)^(n - 2)*(n - 2) : n in [0..30]]; // Wesley Ivan Hurt, Aug 17 2016
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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