A344509 - OEIS

A344509

a(n) = (1/n) * Sum_{k=1..n} k * lcm(k,n).

1, 3, 8, 16, 35, 45, 98, 116, 183, 215, 396, 316, 663, 609, 750, 912, 1513, 1107, 2128, 1560, 2135, 2453, 3818, 2428, 4325, 4095, 4914, 4452, 7743, 4425, 9486, 7280, 8613, 9299, 10640, 8088, 16243, 13053, 14378, 12100, 22181, 12663, 25628, 17996, 19305, 23345, 33558, 19200, 34251, 26075

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..50.

FORMULA

a(n) = A344508(n)/n.

Sum_{k=1..n} a(k) ~ zeta(3) * n^4 / (2*Pi^2). - Vaclav Kotesovec, May 29 2021

MATHEMATICA

a[n_] := Sum[k * LCM[k, n], {k, 1, n}]/n; Array[a, 50] (* Amiram Eldar, May 21 2021 *)

PROG

(PARI) a(n) = sum(k=1, n, k*lcm(k, n))/n;