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 A188195 #7 Mar 30 2012 17:22:57
%S A188195 3,5,6,7,57,102,127,206,217,677,805,840,1486,1680,1887,2090,2834,8329,
%T A188195 10145,12866,21127,23002,50782,67925,82685,96841,153861,178852,357896,
%U A188195 3826652,17985694,38610616,38610808,70587766,160804168,341014432,632582224
%N A188195 Base-3 Keith numbers.
%C A188195 Keith numbers are described in A007629.
%e A188195 57 is here because, in base 3, 57 is 2010 and applying the Keith iteration to this number produces the numbers 2, 0, 1, 0, 3, 4, 8, 15, 30, 57.
%t A188195 IsKeith[n_,b_] := Module[{d, s, k}, d = IntegerDigits[n, b]; s = Total[d]; k = 1; While[AppendTo[d, s]; s = 2 s - d[[k]]; s < n, k++]; s == n]; Select[Range[3,10^5], IsKeith[#,3]&]
%Y A188195 Cf. A007629 (base 10), A162724 (base 2), A187713 (base 5), A188196-A188200.
%K A188195 nonn,base
%O A188195 1,1
%A A188195 _T. D. Noe_, Mar 24 2011