A075776 Numbers k that do not divide phi(Fibonacci(k)).

2, 3, 4, 5, 6, 7, 8, 9, 13, 16, 17, 19, 23, 31, 32, 43, 47, 57, 59, 61, 71, 79, 83, 87, 101, 109, 129, 137, 151, 161, 183, 187, 191, 199, 213, 221, 247, 251, 271, 311, 347, 381, 391, 393, 433, 493, 497, 499, 599, 749, 767, 827, 839, 913, 943, 983, 991, 1017, 1027

Offset: 1

Author

Benoit Cloitre, Oct 09 2002

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..65

Crossrefs

Cf. A000010, A000045, A065449.

Programs

Mathematica

Select[Range[200], !Divisible[EulerPhi[Fibonacci[#]], #] &] (* Amiram Eldar, Jun 26 2022 *)

PARI

isok(n) = eulerphi(fibonacci(n)) % n; \\ Michel Marcus, Nov 29 2013

Extensions

More terms from Michel Marcus, Nov 29 2013

a(43)-a(59) from Amiram Eldar, Jun 26 2022