A366771 Number of divisors of A001045(n) (Jacobsthal numbers).

1, 1, 2, 2, 2, 4, 2, 4, 6, 4, 2, 16, 2, 4, 8, 8, 2, 24, 2, 24, 8, 8, 2, 64, 8, 4, 16, 32, 4, 64, 2, 16, 16, 4, 16, 384, 4, 4, 8, 96, 4, 96, 2, 64, 48, 8, 4, 512, 4, 64, 32, 64, 4, 128, 24, 128, 16, 32, 8, 3072, 2, 4, 48, 64, 32, 256, 4, 64, 16, 256, 4, 6144, 4

Offset

1,3

Links

Amiram Eldar, Table of n, a(n) for n = 1..1122

Formula

a(n) = sigma0(Jacobsthal(n)) = A000005(A001045(n)).

Example

a(9) = 6 because Jacobsthal(9) = 171 has divisors {1, 3, 9, 19, 57, 171}.

Crossrefs

Cf. A000005, A001045, A366769, A366770, A366772, A063375.

Sequence in context: A240039 A369902 A130127 * A217982 A184727 A342457

Adjacent sequences: A366768 A366769 A366770 * A366772 A366773 A366774

Keyword

nonn

Author

Sean A. Irvine, Oct 21 2023

Status

approved