This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A050726 #16 Mar 07 2024 16:41:09
%S A050726 0,1,2,3,4,5,6,7,8,9,10,14,15,16,17,18,19,20,21,22,27,28,29,32
%N A050726 Decimal expansion of 5^n contains no pair of consecutive equal digits (probably finite).
%C A050726 No further terms up to 3000. - _Harvey P. Dale_, May 11 2011
%C A050726 No further terms up to 80000. - _Ivan N. Ianakiev_, Aug 31 2019
%e A050726 5^32 = 23283064365386962890625.
%p A050726 q:= n-> (s-> andmap(i-> s[i]<>s[i+1], [$1..length(s)-1]))(""||(5^n)):
%p A050726 select(q, [$0..200])[]; # _Alois P. Heinz_, Mar 07 2024
%t A050726 Select[Range[0,3000],And@@(First[#]!=Last[#]&/@Partition[ IntegerDigits[ 5^#],2,1])&] (* _Harvey P. Dale_, May 11 2011 *)
%t A050726 Select[Range[0,40],SequenceCount[IntegerDigits[5^#],{x_,x_}]==0&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jun 12 2020 *)
%Y A050726 Cf. A008839, A046263, A046271.
%K A050726 nonn,base
%O A050726 0,3
%A A050726 _Patrick De Geest_, Sep 15 1999