A378134 a(n) is the smallest prime p such that (2*p)^(2^n) + 1 is also prime.

2, 2, 2, 2, 37, 281, 137, 2129, 139, 23, 1231, 1279, 17477

Offset: 0

Author

Juri-Stepan Gerasimov, Nov 17 2024

Keywords

• nonn
• more

Crossrefs

Primes p such that (2*p)^(2^k) + 1 is prime: A005384 (k = 0), A052291 (k = 1), A378146 (k = 2).

If a(n) is the smallest prime number p such that (p*2^m)^(2^n) + 1, then we have:

2, 2, 2, 2, 2 (in case m = 0), where primes of the form (p*2^0)^(2^n)+1 are A019434;

this sequence (in case m = 1).

Cf. A378143.

Extensions

a(11)-a(12) from Michael S. Branicky, Nov 18 2024