A093706 Primes p such that (pp'-1)/2 is prime, where p' denotes the next prime after p.

3, 5, 11, 29, 41, 71, 137, 281, 461, 599, 641, 787, 827, 881, 1091, 1129, 1301, 1409, 1607, 1627, 1951, 2129, 2267, 2357, 2381, 2557, 2687, 2887, 2917, 3469, 3527, 3557, 3581, 3967, 4127, 4229, 4337, 4547, 4889, 5009, 5309, 5741, 6131, 6133, 6247, 6343

Offset: 1

Author

Robert G. Wilson v, Apr 10 2004

Keywords

• nonn

Links

• Hugo Pfoertner, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A048797.

Programs

Mathematica

Prime[ Select[ Range[850], PrimeQ[(Prime[ # ]Prime[ # + 1] - 1)/2] &]]
Transpose[Select[Partition[Prime[Range[900]],2,1],PrimeQ[ (Times@@#- 1)/2]&]][[1]] (* Harvey P. Dale, Sep 17 2011 *)

PARI

isA093706(n) = if(n<3,0,isprime(n) && isprime((n*nextprime(n+1)-1)/2)) \\ Michael B. Porter, Dec 15 2009