

A220586


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.


1



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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OFFSET

1,2


LINKS

Amiram Eldar, Table of n, a(n) for n = 1..500


MATHEMATICA

Select[Range[5000000], PrimeQ[DivisorSigma[1, #] + DivisorSigma[2, #] + DivisorSigma[3, #]]&]


CROSSREFS

Cf. A000040, A000203, A001157, A001158.
Sequence in context: A304856 A115987 A076692 * A054300 A303360 A303442
Adjacent sequences: A220583 A220584 A220585 * A220587 A220588 A220589


KEYWORD

nonn


AUTHOR

Harvey P. Dale, Dec 16 2012


EXTENSIONS

a(1) = 1 added by Amiram Eldar, Aug 07 2019


STATUS

approved



