A372701 a(n) = Sum_{i=1..n} Sum_{j=1..n} Sum_{k=1..n} mu(i*j*k), where mu is the Moebius function A008683.

1, -2, 1, 1, 4, 1, -2, -2, -2, -5, -8, -8, -17, -2, 7, 7, 16, 16, 19, 19, 58, 79, 112, 112, 112, 151, 151, 151, 202, 115, 124, 124, 181, 238, 235, 235, 304, 355, 334, 334, 445, 232, 289, 289, 289, 358, 439, 439, 439, 439, 436, 436, 535, 535, 538, 538, 523, 508, 685, 685, 862, 913, 913, 913, 820, 421

Offset

1,2

Links

Table of n, a(n) for n=1..66.

Mathematica

Table[Sum[MoebiusMu[i*j*k], {i, 1, n}, {j, 1, n}, {k, 1, n}], {n, 1, 80}] (* Vaclav Kotesovec, Jun 01 2024 *)

Prog

(PARI) a(n) = sum(i=1, n, sum(j=1, n, sum(k=1, n, moebius(i*j*k))));

Crossrefs

Cf. A002321, A008683, A372700.

Sequence in context: A301906 A302150 A193554 * A131350 A131087 A105475

Adjacent sequences: A372698 A372699 A372700 * A372702 A372703 A372704

Keyword

sign,changed

Author

Seiichi Manyama, May 10 2024

Status

approved