A366781 Number of prime divisors of A000073(n) (tribonacci numbers) (counted with multiplicity).

0, 0, 1, 2, 1, 1, 4, 3, 4, 1, 2, 6, 3, 3, 8, 5, 2, 3, 4, 4, 3, 6, 4, 3, 4, 4, 3, 8, 4, 5, 11, 6, 4, 4, 10, 5, 5, 5, 9, 4, 2, 4, 2, 6, 5, 4, 11, 11, 2, 6, 7, 9, 3, 5, 9, 6, 2, 3, 5, 8, 12, 5, 11, 12, 4, 2, 4, 6, 3, 3, 6, 6, 2, 10, 7, 8, 7, 5, 12, 7, 4, 2, 6, 4

Offset

2,4

Links

Amiram Eldar, Table of n, a(n) for n = 2..365

Formula

a(n) = A001222(A000073(n)).

Example

a(8)=4 because the 8th tribonacci number 24 = 2^3*3 has 4 prime factors.

Mathematica

PrimeOmega[LinearRecurrence[{1, 1, 1}, {1, 1, 2}, 84]] (* Amiram Eldar, Oct 23 2023 *)

Crossrefs

Cf. A000073, A001222, A022307, A366780, A366782.

Sequence in context: A249577 A225924 A078015 * A240769 A357320 A174455

Adjacent sequences: A366778 A366779 A366780 * A366782 A366783 A366784

Keyword

nonn

Author

Sean A. Irvine, Oct 22 2023

Status

approved