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A128548 Primes p such that p*q-p-q and p*q+p+q are prime where q=nextprime(p). 4

%I

%S 3,5,13,43,89,163,479,643,683,773,811,953,1109,1399,1471,2213,2741,

%T 3253,4583,5153,5923,6427,7649,9059,10151,10531,12301,12373,13553,

%U 13903,13921,14723,14869,14929,16183,17123,17681,21149,21377,21569,21587

%N Primes p such that p*q-p-q and p*q+p+q are prime where q=nextprime(p).

%C Intersection of A126148 and A128546.

%H Charles R Greathouse IV, <a href="/A128548/b128548.txt">Table of n, a(n) for n = 1..10000</a>

%e 3*5-3-5=7 and 3*5+3+5=23 are prime, 5*7-5-23=7 and 5*7+5+7=47 are primes.

%o (PARI) isok(p) = isprime(p) && (q = nextprime(p+1)) && isprime(p*q-p-q) && isprime(p*q+p+q); \\ _Michel Marcus_, Oct 11 2013

%Y Cf. A096342, A126148, A128547.

%K nonn

%O 1,1

%A _Zak Seidov_, Mar 10 2007

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Last modified October 19 15:34 EDT 2021. Contains 348091 sequences. (Running on oeis4.)