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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.

A217178 a(n) is the number of digits in the decimal representation of the smallest power of n that contains three consecutive identical digits.

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%I A217178 #13 Nov 10 2022 11:39:32
%S A217178 8,16,8,35,4,27,8,16,4,9,19,28,17,28,8,15,8,12,4,15,10,21,20,35,16,16,
%T A217178 15,8,5,11,13,16,16,28,15,24,4,20,5,23,7,12,20,30,20,14,29,29,6,26,18,
%U A217178 13,20,44,42,15,20,18,6,25,20,33,8,13,17,24,13,23,6,21
%N A217178 a(n) is the number of digits in the decimal representation of the smallest power of n that contains three consecutive identical digits.
%C A217178 Number of digits in n^k is equal to floor(1 + k*log_10(n)).
%H A217178 V. Raman, <a href="/A217178/b217178.txt">Table of n, a(n) for n = 2..10000</a>
%t A217178 Table[k = 1; While[d = IntegerDigits[n^k]; !  MemberQ[Partition[Differences[d], 2, 1], {0, 0}], k++]; Length[d], {n, 2, 100}] (* _T. D. Noe_, Oct 03 2012 *)
%t A217178 spn3[n_]:=Module[{p=1},While[SequenceCount[IntegerDigits[n^p],{x_,x_,x_}]<1,p++];IntegerLength[n^p]]; Array[spn3,80,2] (* _Harvey P. Dale_, Nov 10 2022 *)
%Y A217178 Cf. A217158, A217168.
%K A217178 nonn,base
%O A217178 2,1
%A A217178 _V. Raman_, Sep 27 2012