A124521 Numbers k such that 16*k - 1 and 16*k + 1 are twin primes.

12, 15, 27, 72, 93, 117, 132, 162, 168, 195, 198, 210, 258, 267, 300, 327, 330, 345, 435, 468, 642, 765, 813, 855, 903, 912, 960, 978, 993, 1128, 1143, 1182, 1290, 1350, 1353, 1365, 1392, 1398, 1440, 1632, 1680, 1713, 1737, 1797, 1848, 1860, 1947, 1953, 1962

Offset: 1

Author

Artur Jasinski, Nov 04 2006

Keywords

• nonn

Examples

			12 is in the sequence since 16*12 - 1 = 191 and 16*12 + 1 = 193 are twin primes.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A040040, A045753, A002822, A124065, A124518, A124519, A124520, A124522, A063983.

Programs

Maple

A124521:=n->`if`(isprime(16*n-1) and isprime(16*n+1), n, NULL): seq(A124521(n), n=1..2000); # Wesley Ivan Hurt, Oct 10 2014

Mathematica

Select[Range[2000], And @@ PrimeQ[{-1, 1} + 16# ] &] (* Ray Chandler, Nov 16 2006 *)

Extensions

Extended by Ray Chandler, Nov 16 2006