A147690 a(0)=1; thereafter a(n+1)=F(n+3)*a(n)+F(n+3) where F_n is Fibonacci's sequence 0,1,1,2,3,5,8, etc

1, 4, 15, 80, 648, 8437, 177198, 6024766, 331362185, 29491234554, 4246737775920, 989489901789593, 373037692974676938, 227552992714552932790, 224594803809263744664717, 358677901683394200229554646, 926823697949890613393169207848

Offset

0,2

Links

Table of n, a(n) for n=0..16.

Formula

a(n) ~ c * ((1 + sqrt(5))/2)^(n*(n+5)/2) / 5^(n/2), where c = 2.8108236954842730572761317698844943576850363911506448409307848569379046... . - Vaclav Kotesovec, May 05 2015

Mathematica

RecurrenceTable[{a[0]==1, a[n+1]==Fibonacci[n+3]*(a[n]+1)}, a, {n, 0, 20}] (* Vaclav Kotesovec, May 05 2015 *)

Prog

(PARI) fa(n) = if (n == 0, 1,  fibonacci(n+2) * (fa(n-1) + 1)); \\ Michel Marcus, Sep 05 2013

Crossrefs

Sequence in context: A232042 A125307 A073479 * A350830 A068313 A174661

Adjacent sequences: A147687 A147688 A147689 * A147691 A147692 A147693

Keyword

nonn

Author

Andrew-David Bjork (abjork(AT)math.uci.edu), Nov 10 2008

Status

approved