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A019422
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Sum of divisors of n is a fourth power.
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9
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1, 217, 510, 642, 710, 742, 782, 795, 862, 935, 1177, 1207, 1219, 2667, 3937, 7590, 7854, 8743, 9481, 9798, 9858, 10810, 10934, 11186, 11235, 11510, 11594, 11715, 11985, 12082, 12243, 12903, 12945, 13022, 13462, 13587, 13685, 13822, 14223, 15085
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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REFERENCES
| J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 217, p. 62, Ellipses, Paris 2008.
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MATHEMATICA
| Select[Range[16000], IntegerQ[Power[DivisorSigma[1, #], (4)^-1]]&] (* From Harvey P. Dale, Jan 22 2012 *)
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CROSSREFS
| Sequence in context: A145732 A038594 A020232 * A101826 A020251 A183778
Adjacent sequences: A019419 A019420 A019421 * A019423 A019424 A019425
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KEYWORD
| nonn
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AUTHOR
| David W. Wilson (davidwwilson(AT)comcast.net)
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