%I #15 Aug 04 2024 20:46:41
%S 1,4,16,80,480,3840,42240,675840,16220160,600145920,34808463360,
%T 3202378629120,470749658480640,111096919401431040,
%U 42216829372543795200,25878916405369346457600,25620127241315652993024000,40992203586105044788838400000
%N a(n) = (1/3)*Product_{k=0..n} (F(k)+3), where F=A000045 (Fibonacci numbers).
%C Trivially, a(n+1)/a(n) is an integer for n>=0, so (a(n)) is a divisibility sequence.
%t q[n_] := Fibonacci[n]
%t p[n_] := Product[q[k] + 3, {k, 0, n}]
%t Table[(1/3)*Simplify[p[n]], {n, 0, 20}]
%o (PARI) a(n) = prod(k=0, n, fibonacci(k)+3)/3; \\ _Michel Marcus_, Aug 04 2024
%Y Cf. A000045, A082480.
%K nonn
%O 0,2
%A _Clark Kimberling_, Aug 03 2024