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A202423 Numbers n such that  n!*n!! + 1 is prime. 0
1, 2, 3, 4, 5, 14, 37, 48, 50, 52, 88, 223 (list; graph; refs; listen; history; text; internal format)
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

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Last modified February 24 09:40 EST 2020. Contains 332209 sequences. (Running on oeis4.)