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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
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
Sequence in context: A093859 A266257 A115905 * A307997 A096134 A058885
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Sep 28 2017
STATUS
approved

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Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)