A076776 - OEIS

%I #7 Jun 07 2021 19:33:55

%S 1,2,5,10,50,500,25000,12500000,312500000000,3906250000000000000,

%T 1220703125000000000000000000000,

%U 4768371582031250000000000000000000000000000000000

%N a(0) = 1, a(1) = 2, a(2) = 5; for n > 2, a(n) = a(n-1)*a(n-2).

%F a(n) = 2^fibonacci(n-2)*5^fibonacci(n-1)for n>=2, fibonacci(n)=A000045(n). - _Vladeta Jovovic_ and Antonio G. Astudillo (afg_astudillo(AT)hotmail.com), Nov 16 2002

%p with(combinat, fibonacci):A076776 := n->2^fibonacci(n-2)*5^fibonacci(n-1);

%t nxt[{a_,b_}]:={b,a*b}; Join[{1},NestList[nxt,{2,5},15][[All,1]]] (* _Harvey P. Dale_, Jun 07 2021 *)

%Y Cf. A000045, A000301, A010098, A010099.

%K nonn

%O 0,2

%A Emily Shields (emilyshields_2001(AT)hotmail.com), Nov 14 2002

%E More terms from Antonio G. Astudillo (afg_astudillo(AT)hotmail.com), Nov 16 2002