A127435 Primes p such that (p-1)^2 + 1 is prime.

2, 3, 5, 7, 11, 17, 37, 41, 67, 127, 131, 151, 157, 181, 211, 241, 251, 257, 271, 281, 307, 397, 401, 421, 431, 467, 491, 557, 571, 577, 647, 691, 701, 751, 761, 827, 907, 911, 937, 947, 967, 1061, 1097, 1151, 1277, 1291, 1307, 1321, 1367, 1567, 1571, 1861

Offset

1,1

Comments

Consists of 3 and a subsequence of A045349.

These are the primes of the form A067720(k)+1. - Michel Marcus, Nov 21 2020

Links

Table of n, a(n) for n=1..52.

Formula

a(n) = sqrt(A127436(n)-1) + 1.

Mathematica

Select[Prime@Range[300], PrimeQ[(# - 1)^2 + 1] &] (* Ray Chandler, Jan 23 2007 *)

Prog

(PARI) listp(nn) = {forprime(p=2, nn, if (isprime((p-1)^2 + 1), print1(p, ", ")); ); } \\ Michel Marcus, Jun 08 2016

Crossrefs

For the associated primes, see A127436.

Cf. A045349, A067720.

Sequence in context: A113016 A085136 A068868 * A257110 A038887 A178991

Adjacent sequences: A127432 A127433 A127434 * A127436 A127437 A127438

Keyword

nonn

Author

Lekraj Beedassy, Jan 14 2007

Extensions

Corrected and extended by Ray Chandler, Jan 23 2007

Status

approved