login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A239002
Number of partitions of n into distinct parts all of which are Fibonacci numbers greater than 1.
9
1, 0, 1, 1, 0, 2, 0, 1, 2, 0, 2, 1, 0, 3, 0, 2, 2, 0, 3, 0, 1, 3, 0, 3, 2, 0, 4, 0, 2, 3, 0, 3, 1, 0, 4, 0, 3, 3, 0, 5, 0, 2, 4, 0, 4, 2, 0, 5, 0, 3, 3, 0, 4, 0, 1, 4, 0, 4, 3, 0, 6, 0, 3, 5, 0, 5, 2, 0, 6, 0, 4, 4, 0, 6, 0, 2, 5, 0, 5, 3, 0, 6, 0, 3, 4, 0, 4
OFFSET
0,6
COMMENTS
a(n) > 0 if n+1 is a term of the lower Wythoff sequence, A000201; a(n) = 0 if n+1 is a term of the upper Wythoff sequence, A001950.
LINKS
FORMULA
G.f.: Product_{i>=3} (1+x^Fibonacci(i)). - Alois P. Heinz, Mar 15 2014
MAPLE
F:= combinat[fibonacci]:
b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<3, 0,
b(n, i-1)+`if`(F(i)>n, 0, b(n-F(i), i-1))))
end:
a:= proc(n) local j; for j from ilog[(1+sqrt(5))/2](n+1)
while F(j+1)<=n do od; b(n, j)
end:
seq(a(n), n=0..100); # Alois P. Heinz, Mar 15 2014
MATHEMATICA
f = Table[Fibonacci[n], {n, 3, 75}]; b[n_] := SeriesCoefficient[Product[1 + x^f[[k]], {k, n}], {x, 0, n}]; u = Table[b[n], {n, 0, 60}] (* A239002 *)
Flatten[Position[u, 0]] (* A001950 *)
CROSSREFS
KEYWORD
nonn,easy,look
AUTHOR
Clark Kimberling, Mar 08 2014
STATUS
approved