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A288450 Numbers k such that k!6 + 48 is prime, where k!6 is the sextuple factorial number (A085158 ). 1
5, 11, 13, 17, 19, 35, 43, 49, 67, 71, 73, 85, 103, 263, 293, 497, 529, 599, 905, 971, 1685, 2927, 3635, 3847, 4535, 8501, 38777 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Corresponding primes are: 53, 103, 139, 983, 1777, 21827623, 2131900273, 104463111073, ...
a(28) > 50000.
Terms > 49 correspond to probable primes.
LINKS
Henri & Renaud Lifchitz, PRP Records. Search for n!6+48.
OpenPFGW Project, Primality Tester
EXAMPLE
11!6 + 48 = 11*5 + 48 = 103 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] + 48] &]
CROSSREFS
Sequence in context: A161548 A090320 A085909 * A346416 A272446 A307390
KEYWORD
nonn,more
AUTHOR
Robert Price, Jun 09 2017
STATUS
approved

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Last modified March 28 15:38 EDT 2024. Contains 371254 sequences. (Running on oeis4.)