A361691 - OEIS

A361691

Number of divisors of 7*n-1 of form 7*k+1.

1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 2, 1, 1, 3, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 3, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 2, 3, 1, 1, 2, 1, 1, 2, 1, 3, 1, 1, 1, 3, 1, 1, 1, 2, 1, 3, 1, 1, 1, 1, 1, 3, 2, 1, 1, 2, 1, 3, 1, 2, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 1

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,7

COMMENTS

Also number of divisors of 7*n-1 of form 7*k+6.

LINKS

Table of n, a(n) for n=1..100.

FORMULA

a(n) = A279061(7*n-1) = A363808(7*n-1).

G.f.: Sum_{k>0} x^(6*k-5)/(1 - x^(7*k-6)).

G.f.: Sum_{k>0} x^k/(1 - x^(7*k-1)).

MATHEMATICA