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”).

A308940
Expansion of e.g.f. 1 / (1 - Sum_{k>=1} Fibonacci(k)*x^k/k!).
0
1, 1, 3, 14, 85, 645, 5878, 62495, 759351, 10379878, 157652085, 2633903669, 48005235886, 947849607015, 20154635314591, 459170181891230, 11158379672316837, 288109467764819749, 7876576756719778854, 227299554620022188879, 6904560742996004248135
OFFSET
0,3
FORMULA
E.g.f.: sqrt(5)/(sqrt(5) - 2*exp(x/2)*sinh(sqrt(5)*x/2)).
a(0) = 1; a(n) = Sum_{k=1..n} binomial(n,k) * Fibonacci(k) * a(n-k).
a(n) ~ n! * 5^((n+1)/2) * (exp(2*r) - 1) / ((sqrt(5) - 1 + (1 + sqrt(5))*exp(2*r)) * 2^n * r^(n+1)), where r = 0.7361181605960590527095268838693519750655284224... is the root of the equation exp(2*r) = 1 + sqrt(5)*exp(r*(1 - 1/sqrt(5))). - Vaclav Kotesovec, Jul 01 2019
MATHEMATICA
nmax = 20; CoefficientList[Series[Sqrt[5]/(Sqrt[5] - 2 Exp[x/2] Sinh[Sqrt[5] x/2]), {x, 0, nmax}], x] Range[0, nmax]!
a[0] = 1; a[n_] := a[n] = Sum[Binomial[n, k] Fibonacci[k] a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 20}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jul 01 2019
STATUS
approved