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Primorials P for which neither P-1 nor P+1 is prime.
5

%I #12 Sep 14 2015 14:41:10

%S 510510,9699690,223092870,6469693230,7420738134810,13082761331670030,

%T 614889782588491410,32589158477190044730,1922760350154212639070,

%U 117288381359406970983270,7858321551080267055879090

%N Primorials P for which neither P-1 nor P+1 is prime.

%C This sequence is different from A121069 and A002110.

%C For almost all primes p, p# is in this sequence by Brun's theorem. - _Charles R Greathouse IV_, Sep 14 2015

%H Charles R Greathouse IV, <a href="/A136352/b136352.txt">Table of n, a(n) for n = 1..350</a>

%F Compute P = product of the first k primes. If P is neither preceded nor followed by a prime add P to the sequence.

%e 13# = 30030 is preceded by a prime but is not followed by a prime. 17# = 510510 is neither preceded nor followed by a prime.

%Y Cf. A136349, A136350, A136351, A002110, A121069.

%K easy,nonn

%O 1,1

%A _Enoch Haga_, Dec 25 2007

%E Edited by and more terms from _Charles R Greathouse IV_, Sep 29 2008