1,3

Alois P. Heinz, Table of n, a(n) for n = 1..10000

a(n) = tau(n^7-1)-tau(n-1), with tau = A000005.

with(numtheory):

a:= n-> add(mobius(7/d) *tau(n^d-1), d={1, 7}):

seq(a(n), n=1..80);

Row n=7 of A212957.

Cf. A000005, A008683.

Sequence in context: A138054 A297927 A321873 * A198418 A086360 A066098

Adjacent sequences: A218253 A218254 A218255 * A218257 A218258 A218259

nonn

Alois P. Heinz, Oct 24 2012

approved