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

%I #7 Jan 29 2016 11:18:44

%S 2,4,12,16,112,124,144,208,228,256,11008,11344,12112,12324,12544,

%T 13648,14032,14896,15132,15376,17152,18256,18688,19152,20176,20452,

%U 20736,32512,32848,34048,38992,39088,39888,40192,40912,42448,42852,43264

%N Monotonic ordering of set S generated by these rules: if x and y are in S then x^2+y^2-xy is in S, and 2 is in S.

%C See A192476.

%t start = {2}; f[x_, y_] := x^2 + y^2 - 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 80000 &]];

%t t = FixedPoint[b, start] (* A192533 *)

%t t/2 (* A192534 *)

%Y Cf. A192476, A192534.

%K nonn

%O 1,1

%A _Clark Kimberling_, Jul 04 2011