A247961 Numbers n such that 45^n + 2 is prime.

0, 1, 2, 3, 4, 38, 40, 104, 114, 135, 417, 1251, 14786, 16720, 43831, 152659

Offset: 1

Author

Vincenzo Librandi, Oct 02 2014

Keywords

• nonn
• more

Comments

Terms of A016969 and A113770 (except 1) are not in the sequence. - Bruno Berselli, Oct 02 2014

a(17) > 2*10^5. - Robert Price, Sep 15 2015

Links

• Henri & Renaud Lifchitz, PRP Top Records, Search for 45^n + 2.

Crossrefs

Cf. similar sequences listed in A247957.

Programs

Magma

[n: n in [0..400]| IsPrime( 45^n + 2 )];

Maple

A247961:=n->`if`(isprime(45^n+2),n,NULL): seq(A247961(n),n=1..500); # Wesley Ivan Hurt, Oct 02 2014

Mathematica

Select[Range[0, 2000], PrimeQ[45^# + 2] &]

PARI

is(n)=ispseudoprime(45^n+2) \\ Charles R Greathouse IV, Jun 06 2017

Extensions

a(13)-a(16) from Robert Price, Sep 15 2015