%I
%S 2,8,38,176,188,866,878,938,4040,4256,4316,4328,4388,4688,19850,19910,
%T 20186,20198,21206,21278,21566,21578,21638,21938,23438,92576,92912,
%U 97820,97880,98900,99176,99248,99260,99536,99548,100916,100928,100988
%N Monotonic ordering of set S generated by these rules: if x and y are in S then 3xyxy is in S, and 2 is in S.
%t start = {2}; f[x_, y_] := 3 x*y  x  y
%t b[x_] :=
%t Block[{w = x},
%t Select[Union[
%t Flatten[AppendTo[w,
%t Table[f[w[[i]], w[[j]]], {i, 1, Length[w]}, {j, 1, i}]]]], # <
%t 1000000 &]];
%t t = NestList[b, start, 12][[1]] (* A192529 *)
%t t/2 (* A192530 *)
%t Table[t[[i]]  t[[i  1]], {i, 2, Length[t]}] (* differences *)
%Y Cf. A192472.
%K nonn
%O 1,1
%A _Clark Kimberling_, Jul 03 2011
