OFFSET
1,1
COMMENTS
By Wilson's theorem, p! == 1 (mod p+2) whenever p, p+2 are twin primes, so 2 is a term.
Terms d > 2 correspond to Wilson's pseudo-twin primes, i.e., consecutive primes p, q such that q - p = d and p! == 1 (mod q). The corresponding primes are listed in A286181 and A286208.
A positive integer d belongs to this sequence if A033312(d-1) = (d-1)! - 1 has a prime factor q such that q - A151799(q) = d.
All terms are even.
If it exists, a(5) >= 140.
CROSSREFS
KEYWORD
bref,nonn,more
AUTHOR
Max Alekseyev, May 04 2017
STATUS
approved