A216968 Numbers n such that 2*n^2 + 3 is prime.
0, 1, 2, 5, 7, 8, 22, 23, 28, 37, 40, 43, 47, 50, 55, 62, 70, 82, 83, 92, 98, 103, 107, 110, 113, 118, 125, 127, 128, 133, 160, 170, 175, 187, 197, 202, 203, 205, 208, 212, 247, 250, 253, 265, 268, 275, 278, 320, 322, 352, 370, 373, 377, 380, 407, 412, 413, 415
Offset: 1
Links
- Zak Seidov, Table of n, a(n) for n = 1..10000
Programs
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Magma
[n: n in [0..500] | IsPrime(2*n^2+3)]; // Bruno Berselli, Sep 21 2012
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Maple
a:= proc(n) option remember; local k; for k from 1+ `if`(n=1, -1, a(n-1)) while not isprime(2*k^2 + 3) do od; k end: seq(a(n), n=1..100); # Alois P. Heinz, Sep 23 2012 -
Mathematica
p=3; s3={}; Do[If[PrimeQ[p + 2 n^2], AppendTo[s3, n]], {n, 0, 500}] Select[Range[0,500],PrimeQ[2#^2+3]&] (* Harvey P. Dale, Nov 24 2013 *) -
PARI
select(n->isprime(2*n^2+3),vector(2000,n,n-1)) /* Joerg Arndt, Sep 21 2012 */