A373003 a(n) = (1/n) * Sum_{k=1..n} tau( (n/gcd(k,n))^n ).

1, 2, 3, 6, 5, 20, 7, 18, 15, 54, 11, 144, 13, 104, 143, 50, 17, 290, 19, 442, 285, 252, 23, 884, 45, 350, 69, 900, 29, 8400, 31, 130, 713, 594, 899, 2622, 37, 740, 999, 2838, 41, 23606, 43, 2296, 2627, 1080, 47, 4884, 91, 2314, 1715, 3234, 53, 3836, 2295, 5880, 2145

Offset

1,2

Links

Table of n, a(n) for n=1..57.

Formula

If p is prime, a(p) = p.

a(n) = (1/n) * Sum_{d|n} phi(d) * tau(d^n).

Prog

(PARI) a(n) = sumdiv(n, d, eulerphi(d)*numdiv(d^n))/n;

Crossrefs

Cf. A344226, A373002.

Sequence in context: A319344 A260443 A328316 * A206242 A327454 A124655

Adjacent sequences: A373000 A373001 A373002 * A373004 A373005 A373006

Keyword

nonn

Author

Seiichi Manyama, May 19 2024

Status

approved