OFFSET
2,1
COMMENTS
In other words, cubefree part of n^3-1, or cubefree kernel of n^3-1. Cube analog of A068310.
LINKS
Robert Israel, Table of n, a(n) for n = 2..10000
EXAMPLE
a(9) = (9^3-1)/8 = (2^3 * 7 * 13)/(2^3) = 728/8 = 91.
a(10) = (10^3-1)/27 = (3^3 * 37)/(3^3) = 999/27 = 37.
a(18) = (18^3-1)/343 = (7^3 * 17)/(7^3) = 5831/343 = 17.
MAPLE
a:= n -> mul(f[1]^(f[2] mod 3), f = ifactors(n^3-1)[2]):
seq(a(n), n=2..100); # Robert Israel, Sep 24 2014
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, Apr 28 2007
EXTENSIONS
More terms from Carl R. White, Nov 09 2010
STATUS
approved