A360277 Primes p that are congruent to 1 mod 2*k, where k = primepi(p) is the index of the prime.

11, 13, 1087, 64591, 64601, 64661, 3523969, 3524249, 189963073, 189963091, 189963847, 189968887, 189969319, 189969337, 1394194181, 1394194481, 1394194561, 1394197381, 1394199221, 1394199241, 10246935931, 10246936019, 10246936481, 75370121689, 75370121857, 75370122409

Offset: 1

Author

Najeem Ziauddin, Feb 01 2023

Keywords

• nonn

Examples

			11 is a term since k = primepi(11) = 5 and 11 == 1 (mod 2*5).
13 is a term since k = primepi(13) = 6 and 13 == 1 (mod 2*6).
64661 is a term since k = primepi(64661) = 6466 and 64661 == 1 (mod 2*6466).
		

Crossrefs

Subsequence of A048891.

Cf. A000040, A000720.

Programs

PARI

lista(pmax) = {my(k = 0); forprime(p = 1, pmax, k+=2; if((p-1)%k==0, print1(p,", "))); } \\ Amiram Eldar, Feb 01 2023

Extensions

a(7)-a(8) from Michel Marcus, Feb 01 2023

a(9)-a(23) from Jon E. Schoenfield, Feb 01 2023

a(24)-a(26) from Amiram Eldar, Feb 01 2023