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 A191284 #7 Nov 17 2016 03:38:27
%S A191284 1,2,3,4,6,8,9,12,13,16,18,19,24,26,27,28,32,36,38,39,40,42,48,52,54,
%T A191284 56,57,58,60,63,64,72,76,78,80,81,84,85,87,90,94,96,104,108,112,114,
%U A191284 116,117,120,121,126,127,128,130,135,141,144,152,156,160,162,168,170,171,174,175,180,181,188,189,190,192,195,202,208,211,216
%N A191284 Increasing sequence generated by these rules: a(1)=1, and if x is in a then floor(3x/2) and 2x are in a.
%C A191284 See A191203.
%H A191284 Ivan Neretin, <a href="/A191284/b191284.txt">Table of n, a(n) for n = 1..10000</a>
%e A191284 1 -> 2,3 -> 4,6 -> 8,9,12 ->
%t A191284 g=16; Union[Flatten[NestList[{Floor[3 #/2], 2#} &, 1, g]]]
%t A191284 (* A191284; use g>15 to get all of first 60 terms *)
%Y A191284 Cf. A191203.
%K A191284 nonn
%O A191284 1,2
%A A191284 _Clark Kimberling_, May 29 2011