A112853
Numbers k such that (2*k)!/k!-1 is prime.
Original entry on oeis.org
2, 6, 14, 25, 114, 188, 193, 361, 712, 1767, 3195, 4995, 5682, 6485, 9937
Offset: 1
Cf.
A112854 primes of the form (2*n)!/n!-1,
A112855 (2*n)!/n!+1 is prime,
A066726 (2*n)!/(n!)^2-1 is prime,
A066699 (2*n)!/(n!)^2+1 is prime,
A112861 (2*n)!/(2*(n!)^2)-1 is prime,
A112863 (2*n)!/(2*(n!)^2)+1 is prime.
A112856
Primes of the form (2*n)!/n!+1.
Original entry on oeis.org
3, 13, 30241, 670442572801, 20007974164906320568399715106816000001, 31370018474571622355156067715319586116075520000001
Offset: 1
Cf.
A112855 n such that (2*n)!/n!+1 is prime,
A112854 primes of the form (2*n)!/n!-1.
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Select[Table[(2n)!/n!+1,{n,50}],PrimeQ] (* Harvey P. Dale, Aug 02 2022 *)
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