%I #8 Sep 15 2018 08:52:41
%S 2,3,5,16,21,185,231,247,252,416,432,437,2495,4345,7648,10143,13568,
%T 17913,19136,26784,29279,33784,33969,34200,34216,34221,52920,53105,
%U 53336,53352,53357,60568,60753,60984,61000,61005,63063,63248,63479
%N Monotonic ordering of set S generated by these rules: if x and y are in S and x^2-y^2>0 then x^2-y^2 is in S, and 2 and 3 are in S.
%C See A192645.
%H Ivan Neretin, <a href="/A192648/b192648.txt">Table of n, a(n) for n = 1..10000</a>
%t start = {2, 3};
%t f[x_, y_] := If[MemberQ[Range[1, 150000], x^2 - y^2], x^2 - y^2]
%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 150000 &]];
%t t = FixedPoint[b, start] (* A192648 *)
%Y Cf. A192476, A192646.
%K nonn
%O 1,1
%A _Clark Kimberling_, Jul 06 2011
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