A227172 Numbers k such that (48^k + 47^k)/95 is prime.

13, 31, 631, 5279, 36781

Offset: 1

Author

Jean-Louis Charton, Jul 03 2013

Keywords

• hard
• nonn
• more

Comments

All terms are prime.

a(5) > 10^4.

Crossrefs

Cf. A000978, A057469, A128066, A128335, A128336, A187805, A181141, A187819, A217095.

Programs

PARI

is(n)=ispseudoprime((48^n+47^n)/95) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(5) from Michael S. Branicky, Jun 23 2025