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

1,1

Comments

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

Links

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

Example

11*13 - 6 = 137 is prime.

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 *)

Prog

(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

Crossrefs

Cf. A092761.

Sequence in context: A141891 A144313 A218561 * A139893 A063312 A210499

Adjacent sequences: A099772 A099773 A099774 * A099776 A099777 A099778

Keyword

nonn

Author

Giovanni Teofilatto, Nov 12 2004

Extensions

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

Status

approved