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A351710
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a(n) = Sum_{p|n, p prime} (n-p)!.
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0
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0, 1, 1, 2, 1, 30, 1, 720, 720, 40440, 1, 3991680, 1, 479006640, 482630400, 87178291200, 1, 22230464256000, 1, 6403681380096000, 6402460884019200, 2432902008216556800, 1, 1175091669949317120000, 2432902008176640000, 620448401733245666380800, 620448401733239439360000
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OFFSET
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1,4
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LINKS
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FORMULA
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EXAMPLE
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a(6) = 30; a(6) = Sum_{p|6} (6-p)! = (6-2)! + (6-3)! = 4*3*2*1 + 3*2*1 = 30.
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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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