A160592 Indices of primes congruent to 7 modulo 12.

4, 8, 11, 14, 19, 22, 27, 31, 34, 36, 38, 46, 47, 48, 58, 61, 63, 67, 73, 75, 85, 90, 93, 95, 99, 101, 105, 111, 114, 115, 117, 125, 129, 131, 133, 138, 141, 143, 149, 153, 155, 157, 163, 167, 175, 177, 179, 181, 188, 193, 202, 207, 210, 213, 217, 222, 224, 229, 232

Offset: 1

Author

M. F. Hasler, May 22 2009

Keywords

• nonn

Comments

The asymptotic density of this sequence is 1/4 (by Dirichlet's theorem). - Amiram Eldar, Mar 02 2021

Examples

			a(1) = 4 since the 4th prime, A000040(4) = 7, is the first one to be equal to 7 (mod 12).
a(2) = 8 since the 8th prime, A000040(8) = 19, is the second one to be equal to 7 (mod 12).
		

Crossrefs

A116615 lists the even terms of this sequence, divided by 2.

Cf. A000720, A068229.

Programs

PARI

for( n=1,999, prime(n)%12==7 & print1(n","))

Formula

a(n) = A000720(A068229(n)).