A247960 Numbers n such that 41^n + 2 is prime.

0, 1, 9, 23, 681, 2487

Offset: 1

Author

Vincenzo Librandi, Sep 29 2014

Keywords

• nonn
• more

Comments

All terms > 0 are odd. - Robert Israel, Sep 29 2014

a(7) > 2*10^5. - Robert Price, May 08 2015

Crossrefs

Cf. similar sequences listed in A247957.

Programs

Magma

[n: n in [0..600]| IsPrime( 41^n + 2 )];

Mathematica

Select[Range[0, 2000], PrimeQ[41^# + 2] &]

PARI

is(n)=ispseudoprime(41^n+2) \\ Charles R Greathouse IV, Jun 13 2017