A278350 Cototient of Fibonacci(n).

0, 0, 1, 1, 1, 4, 1, 9, 18, 15, 1, 96, 1, 41, 370, 435, 1, 1432, 149, 3565, 5906, 287, 1, 33696, 15025, 753, 106562, 129651, 1, 544040, 2973, 960597, 1782178, 5167, 2413385, 10534320, 501497, 1397033, 31758946, 60862155, 62157, 149373496, 1

Offset

1,6

Comments

a(n) = 1 if Fibonacci(n) is prime.

Links

Table of n, a(n) for n=1..43.

Formula

a(n) = A051953(A000045(n)).

a(n) = A000045(n) - A065449(n) for n > 0.

Mathematica

Table[Fibonacci[n] - EulerPhi[Fibonacci[n]], {n, 40}] (* Alonso del Arte, Nov 21 2016 *)

Prog

(PARI) a(n) = fibonacci(n) - eulerphi(fibonacci(n));

Crossrefs

Cf. A000045, A051953, A065449.

Sequence in context: A075150 A001254 A143763 * A128626 A193963 A028941

Adjacent sequences: A278347 A278348 A278349 * A278351 A278352 A278353

Keyword

nonn

Author

Altug Alkan, Nov 19 2016

Status

approved