OFFSET
1,1
COMMENTS
Corresponding primes are: 11, 13, 8513, 623653, 894930583, 8549258359016383, ...
a(24) > 50000.
Terms > 41 correspond to probable primes.
LINKS
Henri & Renaud Lifchitz, PRP Records. Search for n!6+8.
Joe McLean, Interesting Sources of Probable Primes
OpenPFGW Project, Primality Tester
EXAMPLE
21!6 + 8 = 21*15*9*3 + 8 = 8513 is prime, so 21 is in the sequence.
MATHEMATICA
MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[0, 50000], PrimeQ[MultiFactorial[#, 6] + 8] &]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Robert Price, Jun 05 2017
STATUS
approved