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A055707
Numbers k such that k | sigma_13(k) - phi(k)^13.
1
1, 2, 12, 34, 42, 90, 170, 198, 402, 434, 456, 482, 494, 2046, 4086, 4518, 7520, 7605, 8622, 9632, 10924, 28280, 51570, 51714, 74124, 77724, 100172, 139653, 143136, 176760, 294588, 399980, 471826, 675356, 690534, 1358360, 1577696, 2089074, 2121940, 2136256
OFFSET
1,2
COMMENTS
sigma_13(k) is the sum of the 13th powers of the divisors of k (A013961).
LINKS
MATHEMATICA
Do[If[Mod[DivisorSigma[13, n]-EulerPhi[n]^13, n]==0, Print[n]], {n, 1, 10^5}]
PROG
(PARI) isok(n) = !((sigma(n, 13) - eulerphi(n)^13) % n); \\ Michel Marcus, Mar 02 2014
CROSSREFS
Sequence in context: A305330 A320542 A242709 * A055699 A244378 A062094
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Jun 09 2000
EXTENSIONS
Definition corrected and more terms from Michel Marcus, Mar 02 2014
STATUS
approved