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Primes of the form n!*(n+1)! - 1 or n!*(n+1)! + 1.
1

%I #4 Mar 30 2012 18:40:52

%S 2,3,11,13,2879,86399,114000816848279961600001,

%T 2284848632399058501374484565150666260597460935294482959564800000000000001

%N Primes of the form n!*(n+1)! - 1 or n!*(n+1)! + 1.

%C Primes of the form A010790(k)-1 or A010790(k)+1. This is the 2nd sequence in the supersequence whose first member is factorial primes, A002981 UNION A002982. No more through 20!*(20+1)! + 1.

%C a(9) has already 225 digits. The terms are generated by n= 0,1,2,2,4,5,14,32,76,166... [From _R. J. Mathar_, Aug 31 2010]

%F [{A010790(n)-1} INTERSECTION A000040] UNION [{A010790(n)+1} INTERSECTION A000040].

%e a(6) = 86399 because 5!*(5+1)! - 1 = 86399 is prime. a(7) = 114000816848279961600001 because 14!*(14+1)! + 1 = 114000816848279961600001 is prime.

%Y Cf. A000040, A000142, A002981, A002982, A010790.

%K more,nonn

%O 1,1

%A _Jonathan Vos Post_, Apr 07 2010

%E One more term from _R. J. Mathar_, Aug 31 2010