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 A292769 Partial sums of A051612. 2
 0, 2, 4, 9, 11, 21, 23, 34, 41, 55, 57, 81, 83, 101, 117, 140, 142, 175, 177, 211, 231, 257, 259, 311, 322, 352, 374, 418, 420, 484, 486, 533, 561, 599, 623, 702, 704, 746, 778, 852, 854, 938, 940, 1004, 1058, 1108, 1110, 1218, 1233, 1306, 1346, 1420, 1422, 1524, 1556, 1652, 1696, 1758, 1760, 1912 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS N. J. A. Sloane, Table of n, a(n) for n = 1..10000 FORMULA G.f.: (1/(1 - x))*Sum_{k>=1} (1 - mu(k))*x^k/(1 - x^k)^2. - Ilya Gutkovskiy, Sep 28 2017 a(n) ~ c * n^2 + O(n*log(n)), where c = Pi^2/12 - 3/Pi^2 = 0.518503... . - Amiram Eldar, Oct 27 2022 MATHEMATICA Accumulate[Table[DivisorSigma[1, n] - EulerPhi[n], {n, 1, 50}]] (* Amiram Eldar, Oct 27 2022 *) PROG (PARI) lista(nmax) = {my(s = 0, f); for(n = 1, nmax, f = factor(n); s += sigma(f) - eulerphi(f); print1(s, ", ")); } \\ Amiram Eldar, Oct 27 2022 CROSSREFS Cf. A000010, A000203, A051612. Sequence in context: A093859 A266257 A115905 * A307997 A096134 A058885 Adjacent sequences: A292766 A292767 A292768 * A292770 A292771 A292772 KEYWORD nonn AUTHOR N. J. A. Sloane, Sep 28 2017 STATUS approved

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Last modified May 31 23:42 EDT 2023. Contains 363068 sequences. (Running on oeis4.)