A181421 Primes such that the square of the sum of itself and next prime, when added to 1 is a prime.

11, 17, 41, 43, 59, 101, 103, 113, 149, 167, 191, 197, 283, 347, 367, 431, 449, 463, 467, 479, 569, 643, 659, 673, 683, 701, 727, 743, 821, 857, 887, 953, 983, 997, 1031, 1151, 1187, 1213, 1229, 1259, 1301, 1373, 1381, 1423, 1481, 1523, 1531, 1619, 1693, 1733

Offset

1,1

Comments

[p(i)+p(i+1)]^2+1 is a prime.

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Example

a(5)=59 since (59+61)^2+1 = 120^2+1 = 14400+1 = 14401 is a prime.

Prog

(PARI) isok(n) = (isprime(n) && isprime(1+(n + nextprime(n+1))^2)) \\ Michel Marcus, Jul 18 2013
(PARI) p=2; forprime(q=3, 1e4, if(isprime((p+q)^2+1), print1(p", ")); p=q) \\ Charles R Greathouse IV, Aug 26 2013

Crossrefs

Cf. A000040.

Sequence in context: A098649 A078872 A291374 * A290530 A163387 A147253

Adjacent sequences: A181418 A181419 A181420 * A181422 A181423 A181424

Keyword

nonn

Author

Carmine Suriano, Oct 18 2010

Extensions

569 inserted by R. J. Mathar, Oct 18 2010

Status

approved