A192531 Monotonic ordering of set S generated by these rules: if x and y are in S then 3xy-2x-2y is in S, and 2 is in S.

2, 4, 12, 32, 44, 112, 124, 172, 312, 384, 432, 444, 492, 684, 1064, 1112, 1232, 1244, 1472, 1532, 1712, 1724, 1772, 1964, 2732, 2944, 3112, 3784, 3832, 4072, 4192, 4252, 4312, 4432, 4444, 4912, 4924, 4972, 5632, 5824, 5884, 6124, 6832, 6844, 6892

Offset: 1

Author

Clark Kimberling, Jul 04 2011

Keywords

• nonn

Comments

See A192476.

Crossrefs

Cf. A192476, A192532.

Programs

Mathematica

start = {2}; f[x_, y_] := 3 x*y - 2 x - 2 y
b[x_] :=
  Block[{w = x},
   Select[Union[
     Flatten[AppendTo[w,
       Table[f[w[[i]], w[[j]]], {i, 1, Length[w]}, {j, 1, i}]]]], # <
      30000 &]];
t = FixedPoint[b, start] (* A192531 *)
t/2   (* A192532 *)