A383438 - OEIS

A383438

a(n) = Sum_{k=1..n} Product_{p|k, p prime} k/p.

1, 2, 3, 5, 6, 12, 13, 17, 20, 30, 31, 55, 56, 70, 85, 93, 94, 148, 149, 189, 210, 232, 233, 329, 334, 360, 369, 425, 426, 1326, 1327, 1343, 1376, 1410, 1445, 1661, 1662, 1700, 1739, 1899, 1900, 3664, 3665, 3753, 3888, 3934, 3935, 4319, 4326, 4576, 4627, 4731

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..52.

FORMULA

a(n) = Sum_{k=1..n} A205959(k).

MATHEMATICA

a[n_]:=Sum[Product[k/p, {p, Select[Divisors[k], PrimeQ[#] &]}], {k, n}]; Array[a, 52] (* Stefano Spezia, Apr 27 2025 *)

PROG

(SageMath)

from itertools import accumulate