A154403 Number of ways to write n as a sum a_1 + ... + a_k where a_i >= 2 * a_{i-1} > 1.

1, 1, 1, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 5, 6, 6, 7, 8, 8, 9, 11, 11, 12, 14, 14, 15, 17, 18, 19, 22, 23, 24, 27, 28, 30, 33, 35, 37, 40, 42, 44, 48, 50, 53, 58, 60, 63, 68, 71, 74, 80, 84, 87, 93, 97, 101, 107, 112, 117, 124, 129, 135, 143, 148, 155, 164, 170, 177, 187, 194

Offset

0,7

Links

Table of n, a(n) for n=0..70.

Formula

G.f.: x+(1/(1+x))/Product_{k>0}(1-x^(2^k-1)).

Crossrefs

Cf. A000929, A154402.

Sequence in context: A199017 A189709 A025771 * A053265 A035452 A199575

Adjacent sequences: A154400 A154401 A154402 * A154404 A154405 A154406

Keyword

easy,nonn

Author

Vladeta Jovovic, Jan 08 2009

Extensions

More terms from R. J. Mathar, Jan 21 2009

Status

approved