OFFSET
0,3
COMMENTS
Numbers of decimal digits in a(n) for 0 <= n <= 20: 1, 1, 1, 1, 2, 4, 6, 10, 17, 27, 44, 72, 117, 190, 307, 498, 806, 1305, 2112, 3417, 5530. - Robert Israel, Oct 09 2017
LINKS
Robert Israel, Table of n, a(n) for n = 0..16
FORMULA
a(n) = Product_{k=0..n-1} (n-k+1)^Fibonacci(k).
a(n) ~ c^(phi^n) / n, where c = 2.32072822997682611701924627353608916645018... and phi = A001622 is the golden ratio. - Vaclav Kotesovec, Jul 05 2021
MAPLE
f:= proc(n) option remember; n*procname(n-1)*procname(n-2) end proc:
f(0):= 1: f(1):= 1:
map(f, [$0..12]); # Robert Israel, Oct 08 2017
MATHEMATICA
RecurrenceTable[{a[n + 2] == (n + 2) a[n + 1] a[n], a[0] == a[1] == 1}, a, {n, 0, 12}] (* or *)
Table[Product[(n - k + 1)^Fibonacci[k], {k, 0, n - 1}], {n, 0, 12}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Emanuele Munarini, Oct 08 2017
STATUS
approved