A309527 Numbers k such that 6^k + 17 is prime.

1, 2, 3, 5, 8, 10, 19, 27, 79, 198, 565, 787, 2183, 3811, 4748, 6210, 7887, 8965, 13303, 20125, 23433, 28797

Offset: 1

Author

Daniel Starodubtsev, Aug 06 2019

Keywords

• nonn
• more
• hard
• less

Comments

a(20) > 14000. - Daniel Starodubtsev, Apr 17 2020

Examples

			3 is in the sequence because 6^3 + 17 = 233, which is prime.
		

Crossrefs

Cf. A013600, A013607, A059614, A145106, A182331, A217351, A217352.

Programs

PARI

lista(nn)=for(k=0,nn,if(ispseudoprime(6^k+17),print1(k", ")))

Extensions

a(17)-a(18) from Daniel Starodubtsev, Mar 16 2020

a(19) from Daniel Starodubtsev, Apr 17 2020

a(20)-a(22) from Michael S. Branicky, Mar 14 2023