A338175 Primes p such that (p^2+6)/5 is prime.

2, 3, 7, 17, 23, 47, 53, 157, 173, 193, 233, 347, 353, 373, 383, 443, 457, 577, 823, 857, 907, 1117, 1153, 1193, 1223, 1277, 1447, 1453, 1523, 1697, 1733, 1823, 1873, 2027, 2153, 2203, 2293, 2333, 2357, 2467, 2557, 2657, 2683, 2707, 2777, 2797, 2803, 2903, 3217, 3253, 3323, 3407, 3433, 3643, 3673

Offset: 1

Author

J. M. Bergot and Robert Israel, Oct 14 2020

Keywords

• nonn

Comments

All terms end in 2, 3 or 7.

Examples

			a(3)=7 is a member because 7 is prime and (7^2+6)/5 = 11 is prime.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A154418.

Programs

Maple

select(p -> isprime(p) and isprime((p^2+6)/5), [2,seq(seq(10*i+j,j=[3,7]),i=0..1000)]);