A174360 Primes p such that 2*p^2-+15 are also prime.

7, 11, 17, 29, 59, 167, 461, 563, 617, 631, 881, 1303, 2437, 2531, 2671, 2999, 3181, 3191, 3343, 3373, 3917, 4049, 4099, 4409, 5443, 5659, 6199, 7193, 7237, 7507, 7529, 7907, 7963, 8123, 8287, 8707, 8999, 9029, 9461, 11087, 11161, 12379, 13523, 13763

Offset

1,1

Links

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

Example

For p=7, 2*7^2-+15=(83,113); p=11, 2*11^2-+15=(227,257)

Mathematica

Select[Prime[Range[2, 500]], PrimeQ[2 #^2 - 15]&&PrimeQ[2 #^2 + 15]&] (* Vincenzo Librandi, Apr 10 2013 *)

Prog

(Magma) [p: p in PrimesInInterval(3, 15000)|IsPrime(2*p^2-15) and IsPrime(2*p^2+15)];

Crossrefs

Sequence in context: A063912 A078725 A247478 * A320384 A019418 A068674

Adjacent sequences: A174357 A174358 A174359 * A174361 A174362 A174363

Keyword

nonn,easy

Author

Vincenzo Librandi, Mar 17 2010

Status

approved