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A073807
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Number of divisors of sum of cube of divisors.
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0
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1, 3, 6, 2, 12, 18, 8, 12, 2, 20, 18, 12, 8, 24, 36, 4, 32, 6, 24, 24, 24, 30, 36, 72, 4, 24, 32, 16, 24, 60, 36, 16, 60, 48, 60, 4, 16, 72, 24, 80, 24, 72, 24, 36, 24, 60, 60, 24, 8, 12, 96, 16, 20, 96, 80, 96, 50, 40, 72, 72, 16, 108, 16, 8, 54, 100, 12, 64, 108, 100, 32, 24
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OFFSET
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1,2
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LINKS
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Table of n, a(n) for n=1..72.
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FORMULA
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a(n)=A000005[A001158(n)]=d[sigma[3, n]]
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EXAMPLE
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n=10:D={1,2,5,10}, sigma[3,10]=1+8+125+1000=1134, D[1134]={1,2,3,6,7,9,14,18,21,27,42,54,63,81,126, 162,189,378,567,1134} so a(10)=20.
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MATHEMATICA
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Table[DivisorSigma[0, DivisorSigma[3, n]], {n, 80}] (* Harvey P. Dale, Dec 13 2011 *)
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CROSSREFS
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Cf. A000005, A001158, A062068, A073802-A073813.
Sequence in context: A210199 A268717 A002516 * A345671 A090774 A147995
Adjacent sequences: A073804 A073805 A073806 * A073808 A073809 A073810
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KEYWORD
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nonn
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AUTHOR
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Labos Elemer, Aug 13 2002
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STATUS
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approved
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