OFFSET
1,2
COMMENTS
Sequence must be infinite but a proof is needed. Subsidiary sequences; Perfect squares or perfect cubes etc. in which neighboring digits are distinct.
On the other hand, for k >= 22 we might expect only finitely many k-th powers where neighboring digits are distinct (see A318763). - Robert Israel, Sep 03 2018
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
N:= 5000:
filter:= proc(n) local L;
L:= convert(n, base, 10);
not member(0, L[2..-1]-L[1..-2])
end proc:
P:= sort(convert({seq(seq(i^k, i=1..floor(N^(1/k))), k=2..ilog2(N))}, list)):
select(filter, P); # Robert Israel, Sep 03 2018
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Amarnath Murthy, Dec 06 2003
EXTENSIONS
Corrected and extended by Rick L. Shepherd, Jul 01 2005
Offset corrected by Robert Israel, Sep 03 2018
STATUS
approved