A092968 Numbers n such that 2n^2 + 11 is a prime.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 13, 15, 16, 18, 19, 20, 23, 24, 28, 29, 30, 31, 37, 41, 42, 43, 46, 49, 50, 52, 54, 60, 62, 63, 65, 69, 70, 71, 75, 83, 85, 87, 91, 94, 95, 96, 98, 100, 106, 108, 109, 114, 123, 124, 128, 130, 134, 136, 137, 139, 145, 146, 151, 152, 153, 158

Offset: 1

Author

Giovanni Teofilatto, Apr 20 2004

Keywords

• nonn
• easy

Links

• Vincenzo Librandi and Zak Seidov, Table of n, a(n) for n = 1..10000 (First 1000 terms from Vincenzo Librandi.)
• Eric Weisstein's World of Mathematics, Prime-Generating Polynomial

Crossrefs

Cf. A050265.

Programs

Magma

[n: n in [1..160] | IsPrime(2*n^2 + 11)]; // Vincenzo Librandi, Dec 04 2012

Mathematica

Select[Range[0, 200], PrimeQ[2#^2+11]&]

Formula

a(n) = sqrt((A050265(n)-11)/2). - Zak Seidov, Jul 25 2015

Extensions

More terms from T. D. Noe, Dec 31 2004