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A288444
Numbers k such that k!6 + 16 is prime, where k!6 is the sextuple factorial number (A085158 ).
1
1, 3, 7, 9, 11, 13, 15, 21, 23, 35, 37, 39, 47, 49, 59, 111, 117, 163, 287, 311, 601, 635, 855, 895, 2455, 2929, 3369, 7147, 10367, 12311, 13093, 13611, 14431, 17305, 27331
OFFSET
1,2
COMMENTS
Corresponding primes are: 17, 19, 23, 43, 71, 107, 421, 8521, 21521, 21827591, 49579091, 295540261, 42061737041, 104463111041, ...
a(36) > 50000.
Terms > 49 correspond to probable primes.
EXAMPLE
11!6 + 16 = 11*5 + 16 = 71 is prime, so 11 is in the sequence.
MATHEMATICA
MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[0, 50000], PrimeQ[MultiFactorial[#, 6] + 16] &]
Select[Range[1000], PrimeQ[Times@@Range[#, 1, -6]+16]&] (* The program generates the first 24 terms of the sequence. To generate more, increase the Range constant. *)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Robert Price, Jun 09 2017
STATUS
approved