A378490 Least prime p such that p^(2^n) + 2^(2^n) is prime.

3, 3, 3, 13, 89, 29, 37, 113, 113, 13, 1151, 43, 53, 5503

Offset

0,1

Links

Table of n, a(n) for n=0..13.

Formula

a(n) = A132260(n,1) for n>=3.

Example

a(1) = 3, because 3^(2^1) + 2^(2^1) = 13 is prime and no smaller prime satisfies the condition.

Prog

(PARI) a(n) = my(p=2, q=2^n); while (!ispseudoprime(p^q + 2^q), p=nextprime(p+1)); p; \\ Michel Marcus, Nov 28 2024

Crossrefs

Cf. A001146, A132260, A157764, A375215.

Sequence in context: A147823 A341211 A335518 * A269347 A183554 A229847

Adjacent sequences: A378487 A378488 A378489 * A378491 A378492 A378493

Keyword

nonn,more

Author

Jean-Marc Rebert, Nov 28 2024

Status

approved