A272776 Numbers k such that phi(Fibonacci(k)) is a square.

1, 2, 3, 5, 6, 9, 22, 33

Offset: 1

Author

Altug Alkan, May 06 2016

Keywords

• nonn
• more

Comments

Corresponding distinct Fibonacci numbers for listed terms are 1, 2, 5, 8, 34, 17711, 3524578.

a(9) > 1000 (range of the b-file in A065449), if it exists. - R. J. Mathar, May 08 2016

Crossrefs

Cf. A000010, A000045, A000290, A065449.

Programs

PARI

lista(nn) = for(n=1, nn, if(issquare(eulerphi(fibonacci(n))), print1(n, ", ")));