OFFSET
1,1
COMMENTS
Corresponding primes are: 13, 197, 613, 13404133, 24663654373, 37455569511954513919973, ...
a(36) > 10^5.
Terms > 46 correspond to probable primes.
LINKS
Henri & Renaud Lifchitz, PRP Records. Search for n!6-27.
Joe McLean, Interesting Sources of Probable Primes
OpenPFGW Project, Primality Tester
EXAMPLE
14!6 - 27 = 14*8*2 - 27 = 197 is prime, so 14 is in the sequence.
MATHEMATICA
MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[10, 50000], PrimeQ[MultiFactorial[#, 6] - 27] &]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Robert Price, Jul 09 2017
EXTENSIONS
a(35) from Robert Price, Aug 04 2018
STATUS
approved