A152091 Primes which are the sum of cousin prime pairs + 1.

11, 19, 31, 43, 79, 139, 163, 199, 211, 223, 331, 463, 619, 631, 883, 919, 1231, 1291, 1483, 1543, 1723, 1759, 1879, 2179, 2851, 2971, 3163, 3331, 3391, 3571, 3739, 4003, 4483, 4591, 4759, 4783, 4951, 5323, 5419, 5503, 6043, 6079, 6163, 6379, 6691, 7351

Offset

2,1

Comments

3 and 7 are the only cousin primes with another prime (5) between them. - Harvey P. Dale, Jul 28 2012

Links

John Cerkan, Table of n, a(n) for n = 2..10000

Formula

Cousin primes are prime pairs that differ by 4.

Example

prime(2)=3, 3 + 4 = 7, 3 + 7 + 1 = 11, the first term in the sequence.

Mathematica

Join[{11}, Select[Total/@Select[Partition[Prime[Range[600]], 2, 1], Last[#]-First[#]==4&]+1, PrimeQ]] (* Harvey P. Dale, Jul 28 2012 *)

Prog

(PARI) g4(n) = for(x=2, n, p=prime(x); if(isprime(p+4), y=p+p+4+1; if(isprime(y), print1(y", "))))
(PARI) isA152091(n) = if(n%2==0, 0, isprime(n) && isprime((n-5)/2) && isprime((n+3)/2)) \\ Michael B. Porter, Mar 17 2010

Crossrefs

Sequence in context: A049719 A155555 A357426 * A272550 A122869 A106535

Adjacent sequences: A152088 A152089 A152090 * A152092 A152093 A152094

Keyword

nonn

Author

Cino Hilliard, Nov 24 2008

Status

approved