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A139061
Numbers n for which (4+n!)/4 is prime.
25
4, 5, 6, 13, 21, 25, 32, 40, 61, 97, 147, 324, 325, 348, 369, 1290, 1342, 3167, 6612, 8176, 10990
OFFSET
1,1
COMMENTS
For primes of the form (4+k!)/4, see A139060.
a(22) > 25000. - Robert Price, Jan 10 2017
MATHEMATICA
a = {}; Do[If[PrimeQ[(n! + 4)/4], AppendTo[a, n]], {n, 1, 500}]; a
Select[Range[500], PrimeQ[(4+#!)/4]&] (* Harvey P. Dale, Mar 24 2011 *)
PROG
(PARI) for(n=4, 1e3, if(ispseudoprime(n!/4+1), print1(n", "))) \\ Charles R Greathouse IV, Jul 15 2011
KEYWORD
nonn
AUTHOR
Artur Jasinski, Apr 07 2008
EXTENSIONS
More terms from Serge Batalov, Feb 18 2015
a(19) - a(21) from Robert Price, Jan 10 2017
STATUS
approved