A372906 a(n) = Sum_{j=1..n} Sum_{k=1..n} gcd(j,n) * gcd(k,n) / gcd(j*k,n).

1, 5, 11, 21, 29, 55, 55, 82, 97, 145, 131, 231, 181, 275, 319, 312, 305, 485, 379, 609, 605, 655, 551, 902, 681, 905, 819, 1155, 869, 1595, 991, 1184, 1441, 1525, 1595, 2037, 1405, 1895, 1991, 2378, 1721, 3025, 1891, 2751, 2813, 2755, 2255, 3432, 2521, 3405, 3355

Offset

1,2

Links

Seiichi Manyama, Table of n, a(n) for n = 1..1000

Prog

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

Crossrefs

Cf. A372881.

Sequence in context: A099400 A139534 A245773 * A166480 A164096 A298785

Adjacent sequences: A372903 A372904 A372905 * A372907 A372908 A372909

Keyword

nonn,mult

Author

Seiichi Manyama, May 16 2024

Status

approved