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 A217160 #11 Oct 01 2012 14:04:38
%S A217160 220,274,110,125,226,172,105,137,5,156,40,227,196,216,55,235,78,115,5,
%T A217160 104,133,187,126,93,115,110,21,163,5,40,44,159,104,110,113,20,200,205,
%U A217160 5,119,142,116,90,145,156,136,37,86,5,37,62,119,85,91,107,142,40
%N A217160 a(n) is the least value of k such that the decimal expansion of n^k contains five consecutive identical digits.
%H A217160 V. Raman, <a href="/A217160/b217160.txt">Table of n, a(n) for n = 2..10000</a>
%t A217160 Table[k = 1; While[! MemberQ[Partition[Differences[IntegerDigits[n^k]], 4, 1], {0, 0, 0, 0}], k++]; k, {n, 2, 100}] (* _T. D. Noe_, Oct 01 2012 *)
%Y A217160 Cf. A045875, A215727, A215728, A215729, A215730, A215731.
%K A217160 nonn,base
%O A217160 2,1
%A A217160 _V. Raman_, Sep 27 2012