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A126334 Lesser of twin primes (p,q=p+2) such that p*q-p-q and p*q+p+q are primes. 3
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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

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 *)

CROSSREFS

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

Sequence in context: A333269 A319598 A353135 * A068635 A156695 A330251

Adjacent sequences:  A126331 A126332 A126333 * A126335 A126336 A126337

KEYWORD

nonn

AUTHOR

Zak Seidov, Mar 10 2007

EXTENSIONS

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

STATUS

approved

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Last modified August 10 00:32 EDT 2022. Contains 356026 sequences. (Running on oeis4.)