A373060 a(n) = Sum_{1 <= x_1, x_2, x_3 <= n} gcd(x_1, n)/gcd(x_1, x_2, x_3, n).

1, 11, 43, 115, 221, 473, 631, 1139, 1609, 2431, 2531, 4945, 4213, 6941, 9503, 10867, 9521, 17699, 13339, 25415, 27133, 27841, 23783, 48977, 39721, 46343, 55555, 72565, 47909, 104533, 58591, 100979, 108833, 104731, 139451, 185035, 99901, 146729, 181159, 251719

Offset

1,2

Links

Seiichi Manyama, Table of n, a(n) for n = 1..200

Prog

(PARI) a(n) = sum(i=1, n, sum(j=1, n, sum(k=1, n, gcd(i, n)/gcd([i, j, k, n]))));

Crossrefs

Cf. A372952, A373061.

Sequence in context: A352966 A142039 A196153 * A213763 A302226 A201714

Adjacent sequences: A373057 A373058 A373059 * A373061 A373062 A373063

Keyword

nonn,mult

Author

Seiichi Manyama, May 21 2024

Status

approved