OFFSET
1,2
COMMENTS
5 divides a(n) for n > 1.
MATHEMATICA
Select[Range[123020000], PowerMod[19, #^2, #^3]==#^3-1&] (* Harvey P. Dale, May 20 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, May 14 2010
EXTENSIONS
More terms from Max Alekseyev, May 16 2010
STATUS
approved