[go: up one dir, main page]

login
A333591
Alternate multiplying and adding Fibonacci numbers: a(0) = F(0) * F(1), for n >= 0, a(2n+1) = a(2n) + F(2n+2), a(2n+2) = a(2n+1) * F(2n+3).
0
0, 1, 2, 5, 25, 33, 429, 450, 15300, 15355, 1366595, 1366739, 318450187, 318450564, 194254844040, 194254845027, 310224987508119, 310224987510703, 1297050672782249243, 1297050672782256008, 14197516664274574263568, 14197516664274574281279
OFFSET
0,3
EXAMPLE
a(0) = 0 * 1 = 0;
a(1) = 0 + 1 = 1;
a(2) = 1 * 2 = 2;
a(3) = 2 + 3 = 5;
a(4) = 5 * 5 = 25.
MATHEMATICA
a[0] = 0; a[n_] := a[n] = If[EvenQ[n], a[n-1] * Fibonacci[n+1], a[n-1] + Fibonacci[n+1]]; Array[a, 22, 0] (* Amiram Eldar, Mar 28 2020 *)
PROG
(Python)
from sympy import fibonacci
f = [fibonacci(n) for n in range(200)]
def a(n):
out = f[0] * f[1]
for i in range(1, n+1):
if i%2:
out += f[i+1]
else:
out *= f[i+1]
return out
KEYWORD
nonn
AUTHOR
Adnan Baysal, Mar 27 2020
STATUS
approved