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 A217158 #12 Mar 13 2018 19:37:55
%S A217158 24,32,12,50,5,31,8,16,3,8,17,25,14,23,6,12,6,9,3,11,7,15,14,25,11,11,
%T A217158 10,5,3,7,8,10,10,18,9,15,2,12,3,14,4,7,12,18,12,8,17,17,3,15,10,7,11,
%U A217158 25,24,8,11,10,3,14,11,18,4,7,9,13,7,12,3,11,8,13
%N A217158 a(n) is the least value of k such that the decimal expansion of n^k contains three consecutive identical digits.
%H A217158 V. Raman, <a href="/A217158/b217158.txt">Table of n, a(n) for n = 2..10000</a>
%t A217158 Table[k = 1; While[! MemberQ[Partition[Differences[IntegerDigits[n^k]], 2, 1], {0, 0}], k++]; k, {n, 2, 100}] (* _T. D. Noe_, Oct 01 2012 *)
%t A217158 lvk[n_]:=Module[{k=1},While[SequenceCount[IntegerDigits[n^k],{x_,x_,x_}]<1,k++];k]; Array[lvk,80,2] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Mar 13 2018 *)
%Y A217158 Cf. A045875, A215727, A215728, A215729, A215730, A215731.
%K A217158 nonn,base
%O A217158 2,1
%A A217158 _V. Raman_, Sep 27 2012