A132190 - OEIS

A132190

Numbers n such that 7*n^2 + 1 is prime.

2, 4, 8, 10, 12, 14, 18, 20, 22, 26, 30, 34, 44, 46, 58, 66, 68, 70, 74, 76, 78, 84, 90, 96, 100, 106, 108, 110, 120, 128, 134, 140, 146, 152, 154, 156, 158, 162, 164, 168, 174, 184, 186, 188, 196, 200, 202, 210, 216, 228, 232, 238, 250, 252, 260, 262, 264, 268

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

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..58.

EXAMPLE

If n=2 then 7*n^2 + 1 = 29 (prime).

If n=100 then 7*n^2 + 1 = 70001 (prime).

MATHEMATICA

Select[Range[300], PrimeQ[7*#^2 + 1] &] (* Stefan Steinerberger, Jan 02 2008 *)

PROG

(Magma) [ n: n in [0..500] | IsPrime(7*n^2 + 1) ]; // Vincenzo Librandi, Jan 31 2011