A083022 Numbers n such that 4*n^2 - 3 is prime.

2, 4, 5, 7, 10, 13, 16, 17, 20, 22, 23, 29, 32, 34, 40, 43, 44, 46, 49, 55, 56, 59, 62, 64, 68, 70, 71, 73, 82, 86, 95, 97, 101, 103, 104, 109, 110, 125, 127, 133, 134, 148, 149, 152, 155, 160, 161, 163, 164, 166, 170, 175, 178, 181, 185, 208, 209, 218, 220

Offset: 1

Author

Hugo Pfoertner, May 31 2003

Keywords

• nonn
• easy

Links

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

Crossrefs

Cf. A028874.

Programs

Magma

[n: n in [1..300] | IsPrime(4*n^2 - 3)]; // Vincenzo Librandi, Oct 05 2012

Mathematica

Select[Range[300], PrimeQ[4 #^2 - 3] &] (* Vincenzo Librandi, Oct 05 2012 *)

PARI

is(n)=isprime(4*n^2-3) \\ Charles R Greathouse IV, May 22 2017

Formula

a(n) = A028873(n)/2.