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Numbers k such that the decimal expansion of k^5 contains no pair of consecutive equal digits.
2

%I #15 Oct 16 2019 01:31:57

%S 0,1,2,3,4,5,7,8,9,11,13,14,15,16,17,21,22,23,24,25,27,28,31,33,34,35,

%T 37,38,42,45,46,48,49,51,52,53,54,55,57,58,62,64,67,69,72,73,75,77,82,

%U 83,86,87,91,92,96,97,98,105,108,109,112,113,114,121,122,123,124,125

%N Numbers k such that the decimal expansion of k^5 contains no pair of consecutive equal digits.

%H Robert Israel, <a href="/A050744/b050744.txt">Table of n, a(n) for n = 1..10000</a>

%p filter:= proc(n) local L;

%p L:= convert(n^5,base,10);

%p not member(0, L[2..-1]-L[1..-2])

%p end proc:

%p select(filter, [$0..1000]); # _Robert Israel_, Aug 27 2018

%t Select[Range[0,200],SequenceCount[IntegerDigits[#^5],{x_,x_}]==0&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Sep 01 2017 *)

%Y Cf. A050752.

%K nonn,base

%O 1,3

%A _Patrick De Geest_, Sep 15 1999

%E Offset changed to 1 by _Robert Israel_, Aug 27 2018