A058051 a(n) = F(F(F(n))), where F is a Fibonacci number (A000045).

0, 1, 1, 1, 1, 5, 10946, 2211236406303914545699412969744873993387956988653

Offset: 0

Author

Robert G. Wilson v, Nov 18 2000

Keywords

• easy
• nonn

Comments

a(8) = 1695216512..7257812353 has 2288 decimal digits and a(9) = 3525796792..4659808333 has 1191833 decimal digits. - Alois P. Heinz, Nov 11 2015

Crossrefs

Cf. A000045, A007570, A262361.

Programs

Maple

F:= n-> (<<0|1>, <1|1>>^n)[1, 2]:
a:= n-> F(F(F(n))):
seq(a(n), n=0..7);  # Alois P. Heinz, Nov 11 2015

Mathematica

F[0] = 0; F[1] = 1; F[n_] := F[n] = F[n - 1] + F[n - 2]; Table[ F[ F[ F[n] ] ], {n, 0, 10} ]
Table[Nest[Fibonacci,n,3],{n,0,8}] (* Harvey P. Dale, Feb 09 2018 *)

Extensions

Offset corrected by Alois P. Heinz, Nov 11 2015