A160593 Indices of primes congruent to 11 modulo 12.

5, 9, 15, 17, 20, 23, 28, 32, 39, 41, 43, 49, 52, 54, 56, 64, 69, 72, 76, 81, 83, 86, 91, 92, 94, 96, 103, 107, 109, 118, 120, 124, 128, 132, 144, 146, 150, 154, 156, 161, 164, 166, 171, 173, 182, 185, 190, 192, 195, 200, 205, 208, 214, 215, 219, 225, 228, 230, 236

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) = 5 since the 5th prime, A000040(5) = 11, is the first one to be equal to 11 (mod 12).
a(2) = 9 since the 9th prime, A000040(9) = 23, is the second one to be equal to 11 (mod 12).
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

A116610 lists the even terms of this sequence, divided by 2.

Cf. A000720, A068231.

Programs

Mathematica

Position[Mod[Prime[Range[250]],12],11]//Flatten (* Harvey P. Dale, Apr 13 2022 *)

PARI

for( n=1,999, prime(n)%12==11 & print1(n","))

Formula

a(n) = A000720(A068231(n)).