A335976 Numbers k such that Fibonacci(6*k) is not a totient.

0, 11, 13, 17, 29, 31, 41, 43, 47, 53, 61, 71, 73, 79, 81, 83, 89, 97, 101, 103, 107, 113, 121, 131, 137, 139, 141, 149, 151, 157, 167, 173, 191, 193, 199, 223, 229, 233, 239, 241, 243, 257, 263, 271, 281, 283, 293, 311, 313, 317, 321, 331, 339, 347, 349, 353, 373, 389, 397, 401, 419, 421, 431, 433, 443, 449, 457, 461, 479, 487, 509, 521, 541, 557, 573, 577, 587, 599, 613, 617, 619, 631, 641, 643, 653, 661, 673, 733, 739

Offset

1,2

Comments

Conjecture: Sequence contains infinitely many primes.

Links

Table of n, a(n) for n=1..89.

Example

11 is a term since Fibonacci(66) = 27777890035288 is not a totient number.

Prog

(PARI) isok(n) = !istotient(fibonacci(6*n))

Crossrefs

Cf. A000010, A007617, A134492, A280592, A280681.

Sequence in context: A289701 A250402 A356383 * A052031 A166009 A240107

Adjacent sequences: A335973 A335974 A335975 * A335977 A335978 A335979

Keyword

nonn

Author

Altug Alkan, Jul 03 2020

Extensions

a(12)-a(20) from Max Alekseyev, Aug 02 2020

Terms a(21) onward from Max Alekseyev, May 19 2024

Status

approved