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A206033
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a(1) =1; for n>=1: a(n) = product of numbers k <= sigma(n) such that k is not equal to sigma(d) for any divisor d of n where sigma = A000203.
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2
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1, 2, 6, 240, 120, 3326400, 5040, 4151347200, 119750400, 19760412672000, 39916800, 10802449851605508096000000, 6227020800, 1077167364120207360000, 1077167364120207360000, 842072570832352567099392000000, 355687428096000
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OFFSET
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1,2
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COMMENTS
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In sequence A206032 are multiplied all values of sigma(d) of all divisors d of numbers n, in sequence A206031 are multiplied only distinct values of sigma(d) of all divisors d of numbers n and in sequence a(n) are multiplied numbers k (1<=k<=sigma(n)) such that sigma(d) = k has no solution for neither divisor d of number n.
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LINKS
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EXAMPLE
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For n=6 -> divisors d of 6: 1,2,3,6; corresponding values of sigma(d): 1,3,4,12; a(6) = Product of k = 2*5*6*7*8*9*10*11 = 3326400.
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MATHEMATICA
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Table[Times @@ Complement[Range[DivisorSigma[1, n]], DivisorSigma[1, Divisors[n]]], {n, 100}] (* T. D. Noe, Feb 10 2012 *)
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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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