A126334 Lesser of twin primes (p,q=p+2) such that p*q-p-q and p*q+p+q are primes.

3, 5, 17681, 21377, 21587, 33599, 41201, 41411, 70139, 74759, 84629, 109619, 114197, 130619, 155861, 160481, 174467, 219407, 222977, 223439, 230999, 235787, 243431, 284129, 285641, 287279, 300929, 325079, 373211, 386987, 389297, 397151

Offset: 1

Author

Zak Seidov, Mar 10 2007

Keywords

• nonn

Comments

Or, primes p such that p+2, p^2-2 and 2 + 4*p + p^2 are primes. Intersection of A128550 and A128551.

The number of such p's <= 10^n: 2, 2, 2, 2, 11, 56, 320, 1772, ..., . - Robert G. Wilson v, Mar 11 2007

Links

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

Crossrefs

Cf. A096342, A126148, A128547, A128548, A128550, A128551.

Programs

Mathematica

fQ[n_] := Block[{p = Prime[n], q = Prime[n + 1]}, p + 2 == q && PrimeQ[p*q - p - q] && PrimeQ[p*q + p + q]]; lst = {}; Do[ If[ fQ@n == True, AppendTo[lst, Prime@n]; Print@ Prime@n], {n, 39055}] (* Robert G. Wilson v, Mar 11 2007 *)

Extensions

More terms from Robert G. Wilson v, Mar 11 2007