A357210 a(n) = Sum_{k=1..n} prime(k/gcd(n,k)).

2, 4, 7, 11, 19, 22, 43, 46, 66, 68, 131, 90, 199, 158, 187, 223, 383, 242, 503, 320, 441, 478, 793, 436, 824, 716, 879, 734, 1373, 658, 1595, 1118, 1313, 1358, 1579, 1103, 2429, 1776, 1957, 1556, 3089, 1532, 3449, 2192, 2347, 2784, 4229, 2144, 4134, 2882, 3687, 3258, 5591

Offset: 1

Author

Ilya Gutkovskiy, Sep 19 2022

Keywords

• nonn

Comments

Inverse Moebius transform of A127413.

Crossrefs

Cf. A000040, A057661, A127413, A130029, A333558.

Programs

Mathematica

Table[Sum[Prime[k/GCD[n, k]], {k, 1, n}], {n, 1, 53}]

PARI

a(n) = sum(k=1, n, prime(k/gcd(n,k))); \\ Michel Marcus, Sep 20 2022

Formula

a(n) = Sum_{d|n} A127413(d).