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 A191286 #7 Nov 17 2016 03:39:32
%S A191286 1,2,3,5,6,9,10,15,18,26,27,30,37,45,54,78,81,82,90,101,111,135,162,
%T A191286 226,234,243,246,270,303,325,333,405,486,677,678,702,729,730,738,810,
%U A191286 901,909,975,999,1215,1370,1458,2026,2031,2034,2106,2187,2190,2214,2430,2703,2727,2917,2925,2997,3645,4110,4374
%N A191286 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 3x and 1+x^2 are in a.
%C A191286 See A191203.
%H A191286 Ivan Neretin, <a href="/A191286/b191286.txt">Table of n, a(n) for n = 1..10000</a>
%e A191286 1 -> 2,3 -> 5,6,9,10 ->
%t A191286 g = 10; Union[Flatten[NestList[{3 #, 1 + #^2} &, 1, g]]]
%t A191286 (* A191286; use g>9 to get all of first 60 terms *)
%Y A191286 Cf. A191203.
%K A191286 nonn
%O A191286 1,2
%A A191286 _Clark Kimberling_, May 29 2011