A121549 Number of ordered ways of writing n as a sum of two Fibonacci numbers (only one 1 is considered as a Fibonacci number).

0, 1, 2, 3, 2, 3, 2, 2, 2, 3, 2, 0, 2, 2, 2, 3, 0, 2, 0, 0, 2, 2, 2, 2, 0, 3, 0, 0, 2, 0, 0, 0, 0, 2, 2, 2, 2, 0, 2, 0, 0, 3, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 0, 2, 0, 0, 2, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 0, 2, 0, 0, 2, 0, 0, 0, 0, 2, 0, 0, 0

Offset

1,3

Links

Alois P. Heinz, Table of n, a(n) for n = 1..10000

Formula

G.f.: (Sum_{i>=2} x^Fibonacci(i))^2.

a(n) = A121548(n,2).

Example

a(6)=3 because we have 6=1+5=3+3=5+1.

Maple

with(combinat): g:=sum(z^fibonacci(i), i=2..30)^2: gser:=series(g, z=0, 130): seq(coeff(gser, z, n), n=1..126);

Crossrefs

Cf. A000045, A121548, A121550, A357688, A357690, A357691.

Sequence in context: A353526 A244544 A159580 * A244228 A023397 A258115

Adjacent sequences: A121546 A121547 A121548 * A121550 A121551 A121552

Keyword

nonn

Author

Emeric Deutsch, Aug 07 2006

Status

approved