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A287207 Numbers k such that k![6] + 2 is prime, where k![6] = A085158(k) = sextuple factorial. 1
0, 1, 3, 5, 9, 17, 27, 45, 51, 53, 93, 197, 213, 221, 245, 279, 845, 927, 2055, 2895, 3615, 5613, 12753, 15737, 17813, 18545, 22629, 47859, 48797 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

a(30) > 50000.

The first 7 primes associated with this sequence: 3, 3, 5, 7, 29, 937, 229637.

LINKS

Table of n, a(n) for n=1..29.

C. Caldwell and H. Dubner (Eds): The top ten prime numbers: from the unpublished collections of R. Ondrejka (May 2001), Table 21 F, p. 75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[#, 6] + 2] &]

CROSSREFS

Cf. A076185, A085158, A094144, A204657.

Sequence in context: A143105 A032679 A154607 * A298338 A018162 A077879

Adjacent sequences:  A287204 A287205 A287206 * A287208 A287209 A287210

KEYWORD

nonn

AUTHOR

Robert Price, May 21 2017

STATUS

approved

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Last modified June 24 21:16 EDT 2019. Contains 324337 sequences. (Running on oeis4.)