

A202423


Numbers n such that n!*n!! + 1 is prime.


0



1, 2, 3, 4, 5, 14, 37, 48, 50, 52, 88, 223
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OFFSET

1,2


LINKS

Table of n, a(n) for n=1..12.


EXAMPLE

For n = 3, 3!*3!! + 1 = 6*3 + 1 = 19 is prime.


MATHEMATICA

lst={}; Do[If[PrimeQ[n!*n!!+1], AppendTo[lst, n]], {n, 500}]; lst


CROSSREFS

Cf. A000142, A006882, A202422.
Sequence in context: A245447 A037340 A199165 * A171593 A227535 A096774
Adjacent sequences: A202420 A202421 A202422 * A202424 A202425 A202426


KEYWORD

nonn


AUTHOR

Michel Lagneau, Dec 19 2011


STATUS

approved



