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A220586
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Numbers n such that (the sum of the divisors of n) plus (the sum of the squares of the divisors of n) plus (the sum of the cubes of the divisors of n) is a prime number.
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1
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1, 2, 4, 18, 25, 100, 484, 1089, 1156, 2809, 11449, 42025, 52900, 63001, 119716, 120409, 196249, 218089, 220900, 280900, 310249, 407044, 491401, 594441, 632025, 651249, 697225, 1012036, 1062961, 1134225, 1216609, 1240996, 1408969, 1643524, 1646089, 1692601
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listen;
history;
text;
internal format)
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OFFSET
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1,2
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LINKS
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Amiram Eldar, Table of n, a(n) for n = 1..500
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MATHEMATICA
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Select[Range[5000000], PrimeQ[DivisorSigma[1, #] + DivisorSigma[2, #] + DivisorSigma[3, #]]&]
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CROSSREFS
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Cf. A000040, A000203, A001157, A001158.
Sequence in context: A076692 A350629 A357998 * A054300 A303360 A303442
Adjacent sequences: A220583 A220584 A220585 * A220587 A220588 A220589
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KEYWORD
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nonn
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AUTHOR
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Harvey P. Dale, Dec 16 2012
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EXTENSIONS
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a(1) = 1 added by Amiram Eldar, Aug 07 2019
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STATUS
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approved
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