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 A215783 #20 Sep 07 2012 02:18:14 %S A215783 107189,44152,22791,67449,125406,67390,90785,67448,32311,164065 %N A215783 The least k such that the decimal expansion of 3^k contains 9 consecutive n's. %e A215783 3^107189 = 141...2860000000000209...483 (51143 decimal digits, 0's start at position 45713). %Y A215783 Cf. A215727, A215732. %K A215783 nonn,base %O A215783 0,1 %A A215783 _V. Raman_, Aug 23 2012