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Primes of the form (2*n)!/(2*(n!)^2)+1.
2

%I #6 Jun 13 2024 15:00:12

%S 2,11,127,463,20058301,17672631901,16123801841551,

%T 51913710643776705684835561,12738806129490428451365214301,

%U 760401738905937245009910944207609329,740106499224393094996908447741294397438051

%N Primes of the form (2*n)!/(2*(n!)^2)+1.

%t Select[Table[(2n)!/(2(n!)^2)+1,{n,70}],PrimeQ] (* _Harvey P. Dale_, Feb 28 2023 *)

%Y Cf. A001700(n-1)=(2*n)!/(2*(n!)^2), A112863 gives n such that (2*n)!/(2*(n!)^2)+1 is prime, A112862 gives primes of the form (2*n)!/(2*(n!)^2)-1.

%K nonn

%O 1,1

%A _Hugo Pfoertner_, Sep 30 2005