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 A283553 Numbers k such that k![4] + 2 is prime, where k![4] = A007662(k) = quadruple factorial. 10
 0, 1, 3, 5, 7, 9, 11, 13, 15, 19, 27, 29, 31, 43, 53, 75, 143, 169, 185, 235, 259, 363, 365, 457, 493, 573, 777, 1273, 1275, 1865, 3621, 4523, 5291, 5845, 7185, 10183, 12845, 15057, 16281, 17945, 18771, 22479, 27235, 28089, 31557, 39163, 45709, 46329, 52211, 77779 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS a(51) > 10^5. The first 10 primes associated with this sequence: 3, 3, 5, 7, 23, 47, 233, 587, 3467, 65837. LINKS Table of n, a(n) for n=1..50. C. Caldwell and H. Dubner (Eds): The top ten prime numbers: from the unpublished collections of R. Ondrejka (May 2001), Table 21 F, p. 75 Ken Davis, Status of Search for Multifactorial Primes. MATHEMATICA MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]]; Select[Range[0, 50000], PrimeQ[MultiFactorial[#, 4] + 2] &] Select[Range[0, 78000], PrimeQ[Times@@Range[#, 1, -4]+2]&] (* Harvey P. Dale, Aug 16 2023 *) CROSSREFS Cf. A076185, A085158, A094144, A204657. Sequence in context: A192861 A333854 A192868 * A081110 A143449 A033034 Adjacent sequences: A283550 A283551 A283552 * A283554 A283555 A283556 KEYWORD nonn AUTHOR Robert Price, Mar 10 2017 EXTENSIONS a(49)-a(50) from Robert Price, Aug 12 2017 STATUS approved

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Last modified July 25 05:51 EDT 2024. Contains 374586 sequences. (Running on oeis4.)