A126961 Primes p such that (3p)^2 + 2 is not prime.

2, 17, 23, 29, 31, 43, 47, 53, 59, 61, 67, 71, 89, 97, 109, 113, 127, 131, 137, 157, 163, 173, 179, 181, 193, 197, 199, 211, 223, 229, 239, 241, 257, 263, 271, 277, 281, 283, 293, 307, 313, 317, 331, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409

Offset

1,1

References

Garath A. Jones and Mary Jones, Elementary Number Theory, Springer - Verlag London, 1998; p. 35, Exercise 2.17.

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Mathematica

Select[Prime[Range[100]], ! PrimeQ[(3#)^2 + 2] &] (* Harvey P. Dale, Jun 14 2011 *)

Prog

(PARI) g(n) = forprime(x=0, n, y=9*x^2+2; if(!isprime(y), print1(x", ")))
(Magma) [p: p in PrimesUpTo(500) | not IsPrime(9*p^2+2)]; // Vincenzo Librandi, Apr 17 2013

Crossrefs

Sequence in context: A371478 A006029 A332094 * A106622 A040992 A049550

Adjacent sequences: A126958 A126959 A126960 * A126962 A126963 A126964

Keyword

nonn,easy

Author

Cino Hilliard, Mar 19 2007

Status

approved