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%I #8 Dec 23 2024 21:49:47
%S 5,7,8,15,103,179,473,2054,3595,4039
%N Numbers k such that (2k)! - k! - 1 is prime.
%C No more terms up to 5000. The first six terms are as previously stated in A118813. All terms found and primes proved by OpenPFGW.
%C No more terms up to 10000. - _Michael S. Branicky_, Dec 23 2024
%H The OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">OpenPFGW</a>
%e 5 is a term because (2*5)! - 5! - 1 = 3628679 is prime.
%e 4039 is a term because (2*4039)! - 4039! - 1 is prime (28058 digits).
%Y Cf. A118813 (corresponding primes), A237443, A118812.
%K nonn,hard,more
%O 1,1
%A _Rick L. Shepherd_, Feb 16 2014