A099775 Primes of the form pq - 6, where p and q are consecutive primes.

29, 71, 137, 317, 431, 661, 1511, 3121, 3593, 4751, 6551, 8627, 9791, 11657, 16631, 19037, 36857, 41983, 51977, 55681, 57593, 72893, 82913, 95471, 116933, 123191, 159191, 194471, 198901, 205187, 210671, 233267, 256021, 272477, 324893, 364801

Offset: 1

Author

Giovanni Teofilatto, Nov 12 2004

Keywords

• nonn

Comments

Primes of the form prime(k)*prime(k+1) - 6 for some k >= 1. - Jon E. Schoenfield, Jan 17 2015

Examples

			11*13 - 6 = 137 is prime.
		

Links

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

Crossrefs

Cf. A092761.

Programs

Mathematica

f[n_]:=Prime[n]*Prime[n+1]-6; lst={}; Do[If[PrimeQ[f[n]],AppendTo[lst,f[n]]],{n,6!}]; lst (* Vladimir Joseph Stephan Orlovsky, Feb 10 2010 *)

PARI

p=2;forprime(q=3,610,if(isprime(u=p*q-6),print1(u,","));p=q)

PARI

forprime(p=2,1000, q=nextprime(p+1); r=p*q-6; if(isprime(r),print1(r,","))) \\ Rick L. Shepherd, Nov 13 2004

Extensions

Edited and extended by Klaus Brockhaus and Rick L. Shepherd, Nov 13 2004