A361788 Number of divisors of n that are totient values (A002202).

1, 2, 1, 3, 1, 3, 1, 4, 1, 3, 1, 5, 1, 2, 1, 5, 1, 4, 1, 5, 1, 3, 1, 7, 1, 2, 1, 4, 1, 5, 1, 6, 1, 2, 1, 7, 1, 2, 1, 7, 1, 4, 1, 5, 1, 3, 1, 9, 1, 3, 1, 4, 1, 5, 1, 6, 1, 3, 1, 9, 1, 2, 1, 7, 1, 5, 1, 3, 1, 4, 1, 10, 1, 2, 1, 3, 1, 4, 1, 9, 1, 3, 1, 8, 1, 2, 1, 7, 1, 6

Offset

1,2

Links

Table of n, a(n) for n=1..90.

Formula

a(n) <= A000005(n) with equality if n is in A000079.

a(n) = 1 for odd numbers (A005408).

Prog

(PARI) a(n) = sumdiv(n, d, istotient(d));

Crossrefs

Cf. A000005, A000079, A005408.

Sequence in context: A364767 A326154 A306248 * A327513 A327530 A084360

Adjacent sequences: A361785 A361786 A361787 * A361789 A361790 A361791

Keyword

nonn

Author

Michel Marcus, Mar 24 2023

Status

approved