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 A217190 #10 Apr 30 2013 20:16:18
%S A217190 1,2,9,41,163,502,1378,3107,9834,41530,223636,308352,308352
%N A217190 a(n) is the number of digits in the decimal representation of the smallest power of 11 that contains n consecutive identical digits.
%C A217190 Number of digits in 11^k is equal to floor(1 + k*log_10(11)).
%t A217190 k = 0; Join[{1}, Table[While[d = IntegerDigits[11^k]; prt = Partition[Differences[d], n - 1, 1]; ! MemberQ[prt, Table[0, {n - 1}]], k++]; Length[d], {n, 2, 8}]] (* _T. D. Noe_, Oct 03 2012 *)
%Y A217190 Cf. A215731, A215737.
%K A217190 nonn,base
%O A217190 1,2
%A A217190 _V. Raman_, Sep 27 2012
%E A217190 a(10)-a(13) added by _V. Raman_, Apr 30 2012, in correspondence with A215731.