OFFSET
0,3
COMMENTS
This is a supersequence of A038178. Its finiteness stems from the fact that the number of digits of (digital root(x))^y is less than y, for every y > 21.
LINKS
Ivan N. Ianakiev, Table of n, a(n) for n = 0..34
MATHEMATICA
lst={0, 1, 2, 3, 4, 5, 6}; Do[If[7^n==Mod[7^n, 9]^n, AppendTo[lst, 7^n]], {n, 1, 9}]; Do[If[8^n==Mod[8^n, 9]^n, AppendTo[lst, 8^n]], {n, 1, 9}]; Union[Join[lst, Table[9^x, {x, 1, 21}]]]
CROSSREFS
KEYWORD
base,nonn,fini,full
AUTHOR
Ivan N. Ianakiev, Aug 31 2014
STATUS
approved