OFFSET
1,3
COMMENTS
Corresponding primes are: 17, 17, 19, 37, 61, 601, 65851, 40883551, ...
a(44) > 10^5.
Terms > 37 correspond to probable primes.
LINKS
Henri & Renaud Lifchitz, PRP Records. Search for n!4+16.
Joe McLean, Interesting Sources of Probable Primes
OpenPFGW Project, Primality Tester
EXAMPLE
13!4 + 2^4 = 13*9*5*1 + 16 = 601 is prime, so 13 is in the sequence.
MATHEMATICA
MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[0, 50000], PrimeQ[MultiFactorial[#, 4] + 2^4] &]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Robert Price, Aug 22 2017
EXTENSIONS
a(41)-a(43) from Robert Price, Sep 25 2019
STATUS
approved