A260352 Numbers n such that both 2*n^2+11 and 2*(n+1)^2+11 are prime.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 15, 18, 19, 23, 28, 29, 30, 41, 42, 49, 62, 69, 70, 94, 95, 108, 123, 136, 145, 151, 152, 189, 190, 204, 212, 215, 223, 227, 276, 277, 278, 281, 290, 291, 294, 314, 328, 342, 353, 367, 368, 372, 405, 410, 436, 488, 497

Offset: 1

Author

Zak Seidov, Jul 23 2015

Keywords

• nonn
• easy

Comments

Both n and n+1 are terms in A092968.

Links

• Zak Seidov, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A092968.

Programs

Magma

[n: n in [0..600]| IsPrime( 2*n^2+11) and IsPrime(2*(n+1)^2+11)]; // Vincenzo Librandi, Jul 26 2015

Mathematica

Select[Range[0, 600], PrimeQ[2 #^2 + 11] &&  PrimeQ[2 (# + 1)^2 + 11] &] (* Vincenzo Librandi, Jul 26 2015 *)

PARI

isok(n) = isprime(2*n^2+11) && isprime(2*(n+1)^2+11); \\ Michel Marcus, Jul 26 2015