A111431 a(n) = Fibonacci(tribonacci(n)).

0, 0, 1, 1, 1, 3, 13, 233, 46368, 701408733, 37889062373143906, 6161314747715278029583501626149, 818706854228831001753880637535093596811413714795418360007

Offset

0,6

Links

Alois P. Heinz, Table of n, a(n) for n = 0..16

Formula

a(n) = A000045(A000073(n)).

Example

a(0) = Fibonacci(tribonacci(0)) = A000045(A000073(0)) = A000045(0) = 0.
a(1) = Fibonacci(tribonacci(1)) = A000045(A000073(1)) = A000045(0) = 0.
a(2) = Fibonacci(tribonacci(2)) = A000045(A000073(2)) = A000045(1) = 1.
a(3) = Fibonacci(tribonacci(3)) = A000045(A000073(3)) = A000045(1) = 1.
a(4) = Fibonacci(tribonacci(4)) = A000045(A000073(4)) = A000045(2) = 1.
a(5) = Fibonacci(tribonacci(5)) = A000045(A000073(5)) = A000045(4) = 3.
a(6) = Fibonacci(tribonacci(6)) = A000045(A000073(6)) = A000045(7) = 13.
a(7) = Fibonacci(tribonacci(7)) = A000045(A000073(7)) = A000045(13) = 233.
a(8) = A000045(A000073(8)) = A000045(24) = 46368.
a(9) = A000045(A000073(9)) = A000045(44) = 701408733.
a(10) = A000045(A000073(10)) = A000045(81) = 37889062373143906.

Maple

a:= n-> (<<0|1>, <1|1>>^((<<0|1|0>, <0|0|1>, <1|1|1>>^n)[1, 3]))[1, 2]:
seq(a(n), n=0..13);  # Alois P. Heinz, Aug 09 2018

Mathematica

Fibonacci/@LinearRecurrence[{1, 1, 1}, {0, 0, 1}, 15] (* Harvey P. Dale, Jan 04 2013 *)

Crossrefs

Cf. A000045, A000073, A066178, A007570, A111425.

Sequence in context: A165903 A100441 A036680 * A015701 A220294 A006487

Adjacent sequences: A111428 A111429 A111430 * A111432 A111433 A111434

Keyword

easy,nonn

Author

Jonathan Vos Post, Nov 13 2005

Status

approved