A361680 The n-th prime p such that p + 2^n is also prime.

3, 7, 11, 31, 47, 67, 83, 163, 179, 193, 263, 367, 389, 499, 563, 571, 887, 967, 1229, 1087, 1367, 1873, 1289, 2647, 1907, 2083, 1979, 2557, 2267, 3697, 2909, 3121, 3761, 4507, 4373, 4723, 5279, 5857, 6359, 6793, 7727, 8167, 7853, 6823, 6779, 8059, 9479, 10567

Offset: 1

Author

Alois P. Heinz, Mar 20 2023

Keywords

• nonn

Comments

This sequence is non-monotonic: a(19) = 1229 > a(20) = 1087.

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..1000

Crossrefs

Main diagonal of A361679.

Cf. A000040.

Programs

Maple

b:= proc() option remember; local f; f:= proc() [] end;
      proc(n, k) option remember; local p;
        p:= `if`(nops(f(k))=0, 1, f(k)[-1]);
        while nops(f(k)) b(n$2):
seq(a(n), n=1..55);

Formula

a(n) = A361679(n,n).