%I A006794 M2474
%S A006794 3,5,11,13,41,89,317,337,991,1873,2053,2377,4093,4297,4583,6569,
%T A006794 13033,15877
%N A006794 Primes p such that -1 + product of primes up to p is prime.
%C A006794 Or, p such that primorial(p) - 1 is prime.
%D A006794 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A006794 C. K. Caldwell, On The Primality of n!+- 1 and 2\cdot 3 \cdot 5\cdots 
               p+- 1, Math. Comput. 64, 889-890, 1995.
%D A006794 C. K. Caldwell and Y. Gallot, On the primality of n!+-1 and 2*3*5*...*p+-1, 
               Math. Comp., 71 (2001), 441-448.
%D A006794 H. Dubner, Factorial and primorial primes, J. Rec. Math., 19 (No. 3, 
               1987), 197-203.
%D A006794 R. K. Guy, Unsolved Problems in Number Theory, Section A2.
%H A006794 C. K. Caldwell, <a href="http://primes.utm.edu/glossary/page.php?sort=PrimorialPrime">
               Primorial Primes</a>
%H A006794 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Primorial.html">Link to a section of The World of Mathematics.</a>
%Y A006794 A057704 gives same sequence in a different way. A057705 gives the actual 
               primes. Cf. A002110, A005234, A014545, A018239.
%Y A006794 Sequence in context: A105071 A089251 A147568 this_sequence A032457 A122564 
               A162876
%Y A006794 Adjacent sequences: A006791 A006792 A006793 this_sequence A006795 A006796 
               A006797
%K A006794 nonn,hard,nice
%O A006794 1,1
%A A006794 N. J. A. Sloane (njas(AT)research.att.com).
%E A006794 Stated incorrectly in CRC Standard Mathematical Tables and Formulae, 
               30th ed., 1996, p. 101; corrected in 2nd printing.
%E A006794 Corrected by Arlin Anderson (starship1(AT)gmail.com), who reports that 
               he and Don Robinson have checked this sequence through about 63000 
               digits without finding another term (Jul 04 2000).