A092350 a(n) = sigma_3(n) - sigma_2(n) - sigma_1(n).

-1, 1, 14, 45, 94, 190, 286, 485, 653, 986, 1198, 1806, 2014, 2822, 3244, 4309, 4606, 6319, 6478, 8610, 9100, 11342, 11614, 15470, 15069, 18890, 19580, 24006, 23518, 30380, 28798, 36021, 36028, 42722, 41996, 53259, 49246, 59870, 59788, 71410, 67198, 84092, 77614

Offset

1,3

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

a(n) = A001158(n) - A001157(n) - A000203(n). - Wesley Ivan Hurt, Nov 16 2021

Dirichlet g.f.: zeta(s) * (zeta(s-3) - zeta(s-2) - zeta(s-1)). - Amiram Eldar, Jan 03 2025

Mathematica

Table[DivisorSigma[3, n] - DivisorSigma[2, n] - DivisorSigma[1, n], {n, 60}] (* Wesley Ivan Hurt, Nov 16 2021 *)

Prog

(PARI) a(n) = my(f = factor(n)); sigma(f, 3) - sigma(f, 2) - sigma(f, 1); \\ Amiram Eldar, Jan 03 2025

Crossrefs

Cf. A000203 (sigma), A001157 (sigma_2(n)), A001158 (sigma_3(n)).

Sequence in context: A328243 A369240 A123295 * A090197 A010742 A232872

Adjacent sequences: A092347 A092348 A092349 * A092351 A092352 A092353

Keyword

sign,easy

Author

N. J. A. Sloane, Mar 20 2004

Status

approved