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%I #13 Jun 13 2022 15:44:45
%S 2,5,19,193,1801,56240459218944001,
%T 112873711099106889552388221969528619131820978659655680000000000001
%N Primes of the form n!*n!! + 1.
%C For n > 4, the last digits of the prime numbers are of the form 01, 001, 0000000000001,...,...000001.
%C Generated by n = 1, 2, 3, 4, 5, 14, 37, 48, 50, 52,... - R. J. Mathar, Dec 21 2011
%C The next term (a(8)) has 93 digits. - _Harvey P. Dale_, Jun 13 2022
%e 19 is in the sequence because, for n = 3, 3!*3!! + 1 = 6*3 + 1 = 19.
%t a={}; Do[p=n!*n!!+1; If[PrimeQ[p], AppendTo[a, p]], {n, 10^3}]; Print[a];
%t Select[Table[n! n!!+1,{n,40}],PrimeQ] (* _Harvey P. Dale_, Jun 13 2022 *)
%Y Cf. A000142, A006882.
%K nonn
%O 1,1
%A _Michel Lagneau_, Dec 19 2011
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