OFFSET
1,1
COMMENTS
For n > 4, the last digits of the prime numbers are of the form 01, 001, 0000000000001,...,...000001.
Generated by n = 1, 2, 3, 4, 5, 14, 37, 48, 50, 52,... - R. J. Mathar, Dec 21 2011
The next term (a(8)) has 93 digits. - Harvey P. Dale, Jun 13 2022
EXAMPLE
19 is in the sequence because, for n = 3, 3!*3!! + 1 = 6*3 + 1 = 19.
MATHEMATICA
a={}; Do[p=n!*n!!+1; If[PrimeQ[p], AppendTo[a, p]], {n, 10^3}]; Print[a];
Select[Table[n! n!!+1, {n, 40}], PrimeQ] (* Harvey P. Dale, Jun 13 2022 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, Dec 19 2011
STATUS
approved