A083022 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

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

FORMULA

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

MATHEMATICA

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

PROG

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

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