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A055697
Numbers k such that k | sigma_3(k) - phi(k)^3.
2
1, 2, 10, 12, 78, 198, 1278, 1470, 1491, 2376, 2472, 6768, 7659, 7774, 9858, 10912, 11904, 12862, 16660, 25758, 35586, 38976, 39102, 40986, 41144, 44688, 59520, 72961, 80304, 84084, 94365, 104328, 119070, 153370, 174966, 200970, 230040, 291696, 358680, 376404
OFFSET
1,2
COMMENTS
sigma_3(k) is the sum of the cubes of the divisors of n (A001158).
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..282 (terms below 10^10)
MATHEMATICA
Do[If[Mod[DivisorSigma[3, n]-EulerPhi[n]^3, n]==0, Print[n]], {n, 1, 2*10^5}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Jun 09 2000
EXTENSIONS
More terms from Sean A. Irvine, Apr 03 2022
STATUS
approved