OFFSET
1,1
COMMENTS
All terms have last digit 2, 3, 7 or 8.
Sequence is likely to be finite. If it exists, a(13) > 10^7.
In this sequence, the only terms with no repeated digits are 3, 7, 8, 43, 93. - Altug Alkan, Jan 26 2017
EXAMPLE
43 is a term because 43^7 = 271818611107 has no digit 4 or 3.
MAPLE
select(t -> convert(convert(t, base, 10), set) intersect convert(convert(t^7, base, 10), set) = {},
{seq(seq(10*i+j, j=[2, 3, 7, 8]), i=0..10^4});
MATHEMATICA
Select[Range[40000], Intersection[IntegerDigits[#], IntegerDigits[ #^7]] == {}&] (* Vincenzo Librandi, Jan 27 2017 *)
PROG
(PARI) isok(n) = #setintersect(Set(digits(n)), Set(digits(n^7))) == 0; \\ Michel Marcus, Jan 26 2017
CROSSREFS
KEYWORD
nonn,more,base
AUTHOR
Robert Israel, Jan 26 2017
STATUS
approved