OFFSET
1,1
COMMENTS
The search for multifactorial primes started by Ray Ballinger is now continued by a team of volunteers on the website of Ken Davis (see link).
LINKS
Robert Price, Table of n, a(n) for n = 1..63
Ken Davis, Status of Search for Multifactorial Primes.
Ken Davis, Results for n!5-1.
MATHEMATICA
MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[0, 1000], PrimeQ[MultiFactorial[#, 5] - 1] & ] (* Robert Price, Apr 19 2019 *)
CROSSREFS
KEYWORD
hard,nonn
AUTHOR
Hugo Pfoertner, Jun 23 2003
EXTENSIONS
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 03 2008
a(54)-a(63) from Ken Davis link added to b-file by Robert Price, Sep 23 2012
STATUS
approved