%I

%S 1,2,4,5,7,13,40,124,758,940

%N Numbers n such that !n + 2n - 1 is prime.

%t Do[ If[ PrimeQ[ Sum[ k!, {k, 0, n - 1} ] + 2n - 1 ], Print[ n ] ], {n, 1, 883} ]

%Y Cf. A063106.

%K nonn

%O 1,2

%A _Robert G. Wilson v_, Aug 09 2001