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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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS For primes of the form (4+k!)/4, see A139060. a(22) > 25000. - Robert Price, Jan 10 2017 LINKS 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 CROSSREFS Cf. A082672, A089085, A089130, A117141, A007749, A139056, A139057, A139058, A139059, A139060, A139061, A139061, A139062, A139063, A139064, A139065, A139066, A020458, A139068, A137390, A139070, A139071, A139072. Cf. n!/m-1 is a prime: A002982, A082671, A139056, A139199-A139205; n!/m+1 is a prime: A002981, A082672, A089085, A139061, A139058, A139063, A139065, A151913, A137390, A139071 (1<=m<=10). Sequence in context: A063833 A260107 A167434 * A029645 A191208 A242077 Adjacent sequences:  A139058 A139059 A139060 * A139062 A139063 A139064 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

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Last modified February 26 17:19 EST 2020. Contains 332293 sequences. (Running on oeis4.)