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A153824
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Sum of proper divisors of n!: a(n) = sigma(n!) - n!.
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2
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0, 0, 1, 6, 36, 240, 1698, 14304, 118800, 1118160, 11705288, 144092256, 1738439808, 24817158912, 355309325280, 5378578601760, 86081749397280, 1570394279039040, 28281459220193088, 572031558109589760, 11458497230555094720
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OFFSET
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0,4
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COMMENTS
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a(n) is the sum of proper divisors of factorial number A000142(n).
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LINKS
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FORMULA
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MAPLE
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with(numtheory): seq(sigma(factorial(n))-factorial(n), n = 0 .. 22); # Emeric Deutsch, Jan 07 2009
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MATHEMATICA
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Table[DivisorSigma[1, n!] - n!, {n, 0, 50}] (* G. C. Greubel, Aug 30 2016 *)
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PROG
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(Magma) [DivisorSigma(1, Factorial(n)) - Factorial(n): n in [0..20]]; // Vincenzo Librandi, Aug 31 2016
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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