A059670 Numbers k such that F(k)*2^k + 1 (A006483) is prime, where F(k) is the k-th Fibonacci number.

1, 2, 3, 13, 16, 20, 28, 83, 136, 300, 765, 1005, 1395, 3333, 30259

Offset: 1

Author

Robert G. Wilson v, Feb 05 2001

Keywords

• nonn
• more

Comments

a(15) > 17000. - Michael S. Branicky, Oct 02 2022

Crossrefs

Cf. A000045, A006483.

Programs

Mathematica

Do[ If[ PrimeQ[ Fibonacci[ n ]*2^n + 1 ], Print[ n ] ], {n, 1, 3000} ]

Python

from sympy import fibonacci, isprime
def ok(n): return isprime(fibonacci(n)*2**n + 1)
print([k for k in range(1400) if ok(k)]) # Michael S. Branicky, Oct 01 2022

Extensions

a(14) from Michael S. Branicky, Oct 02 2022

a(15) from Michael S. Branicky, May 29 2023