A238496 Number of prime factors in A052129(n).

0, 0, 1, 3, 8, 17, 36, 73, 149, 300, 602, 1205, 2413, 4827, 9656, 19314, 38632, 77265, 154533, 309067, 618137, 1236276, 2472554, 4945109, 9890222, 19780446, 39560894, 79121791, 158243585, 316487171, 632974345, 1265948691, 2531897387

Offset

0,4

Links

Table of n, a(n) for n=0..32.

Formula

a(n) = 2*a(n-1) + A001222(n) for n>=1; a(0) = 0.

a(n) = Sum_{i=1..n} 2^(n-i)*A001222(i). - Ridouane Oudra, Nov 11 2019

Maple

with(numtheory): seq(add(2^(n-i)*bigomega(i), i=1..n), n=0..40); # Ridouane Oudra, Nov 11 2019

Prog

(PARI) a(n) = if (n==0, 0, 2*a(n-1) + bigomega(n)); \\ Michel Marcus, May 25 2014

Crossrefs

Cf. A001222, A052129, A238462.

Sequence in context: A147419 A106691 A140176 * A097391 A202554 A034481

Adjacent sequences: A238493 A238494 A238495 * A238497 A238498 A238499

Keyword

nonn,easy

Author

Bob Selcoe, Feb 27 2014

Status

approved