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A015774
Numbers k such that phi(k) | sigma_15(k).
14
1, 2, 3, 6, 12, 14, 15, 30, 35, 38, 42, 46, 54, 56, 70, 78, 87, 95, 105, 114, 126, 134, 135, 138, 140, 147, 161, 168, 174, 182, 184, 190, 209, 210, 215, 216, 222, 230, 248, 258, 264, 270, 285, 294, 297, 299, 315, 322, 357, 398, 402, 414, 418, 420
OFFSET
1,2
COMMENTS
sigma_15(n) is the sum of the 15th powers of the divisors of n.
LINKS
MATHEMATICA
Select[Range[420], Divisible[DivisorSigma[15, #], EulerPhi[#]] &] (* Amiram Eldar, Nov 02 2019 *)
KEYWORD
nonn
EXTENSIONS
Offset corrected by Amiram Eldar, Nov 02 2019
STATUS
approved