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 A359052 a(n) = Sum_{d|n} sigma_d(d)^n. 3
 1, 26, 21953, 5554572467, 298500366308609377, 11413459460309090641106905930, 256925761343390078522337875137209684721665, 6476754651706496208416137876625690606583079440495100502628 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Seiichi Manyama, Table of n, a(n) for n = 1..26 FORMULA G.f.: Sum_{k >= 1} (sigma_k(k) * x)^k/(1 - (sigma_k(k) * x)^k). MATHEMATICA a[n_] := DivisorSum[n, DivisorSigma[#, #]^n &]; Array[a, 8] (* Amiram Eldar, Aug 27 2023 *) PROG (PARI) a(n) = sumdiv(n, d, sigma(d, d)^n); (PARI) my(N=10, x='x+O('x^N)); Vec(sum(k=1, N, (sigma(k, k)*x)^k/(1-(sigma(k, k)*x)^k))) CROSSREFS Cf. A344060, A359053, A359054. Sequence in context: A015035 A336248 A359054 * A209961 A302396 A208186 Adjacent sequences: A359049 A359050 A359051 * A359053 A359054 A359055 KEYWORD nonn AUTHOR Seiichi Manyama, Dec 14 2022 STATUS approved

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Last modified August 10 02:46 EDT 2024. Contains 375044 sequences. (Running on oeis4.)