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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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS sigma_13(k) is the sum of the 13th powers of the divisors of k (A013961). LINKS Amiram Eldar, Table of n, a(n) for n = 1..100 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 Cf. A000010, A013961. Sequence in context: A305330 A320542 A242709 * A055699 A244378 A062094 Adjacent sequences: A055704 A055705 A055706 * A055708 A055709 A055710 KEYWORD nonn AUTHOR Robert G. Wilson v, Jun 09 2000 EXTENSIONS Definition corrected and more terms from Michel Marcus, Mar 02 2014 STATUS approved

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Last modified March 21 19:39 EDT 2023. Contains 361410 sequences. (Running on oeis4.)