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

1,1

Links

Table of n, a(n) for n=1..26.

Example

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).

Prog

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

Crossrefs

Subsequence of A048891.

Cf. A000040, A000720.

Sequence in context: A111070 A110115 A073765 * A174831 A343838 A360388

Adjacent sequences: A360274 A360275 A360276 * A360278 A360279 A360280

Keyword

nonn

Author

Najeem Ziauddin, 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

Status

approved