OFFSET
1,2
LINKS
Robert Price, Table of n, a(n) for n = 1..446 (terms 1..119 from R. J. Mathar).
EXAMPLE
9^(2^2) - 1 = 6560, which is divisible by 2^3, so 2 is in the sequence.
9^(4^2) - 1 = 1853020188851840, which is divisible by 4^3, so 4 is in the sequence.
9^(6^2) - 1 = 22528399544939174411840147874772640, which is not divisible by 6, and certainly not by 6^3, so 6 is not in the sequence.
MAPLE
A177909:=n->`if`(9^(n^2)-1 mod n^3 = 0, n, NULL): seq(A177909(n), n=1..1000); # Wesley Ivan Hurt, Oct 04 2014
MATHEMATICA
Select[Range[100], Divisible[9^(#^2) - 1, #^3] &] (* Alonso del Arte, Oct 04 2014 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, May 14 2010
STATUS
approved