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A063442 Primes of the form p*q+4 where p and q are consecutive primes. 2
19, 1151, 4091, 30971, 47057, 55691, 141371, 148991, 223697, 256031, 265193, 329471, 355211, 948671, 1223231, 1545017, 1607747, 1653791, 2062091, 2238011, 2390111, 2572811, 3041531, 3625211, 4305593, 4553951, 5541311, 5635871 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..1000

EXAMPLE

prime(449) * prime(450) + 4 = 3169 * 3181 + 4 = 10080593, a prime.

MATHEMATICA

f[n_]:=Prime[n]*Prime[n+1]+4; lst={}; Do[If[PrimeQ[f[n]], AppendTo[lst, f[n]]], {n, 6!}]; lst (* Vladimir Joseph Stephan Orlovsky, Feb 10 2010 *)

PROG

(PARI) j=[]; for(n=1, 500, x=(prime(n)*prime(n+1))+4; if(isprime(x), j=concat(j, x))); j

(PARI) { n=0; for (m=1, 10^9, if (isprime(a=prime(m)*prime(m + 1) + 4), write("b063442.txt", n++, " ", a); if (n==1000, break)) ) } \\ Harry J. Smith, Aug 21 2009

CROSSREFS

Sequence in context: A098635 A217828 A217829 * A091750 A316332 A319025

Adjacent sequences:  A063439 A063440 A063441 * A063443 A063444 A063445

KEYWORD

easy,nonn

AUTHOR

Jason Earls, Jul 23 2001

STATUS

approved

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Last modified June 24 04:38 EDT 2019. Contains 324318 sequences. (Running on oeis4.)