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Monotonic ordering of set S generated by these rules: if x and y are in S then 5xy-x-y is in S, and 1 is in S.
2

%I #5 Mar 30 2012 18:57:34

%S 1,3,11,39,43,151,155,171,543,583,599,603,619,683,2095,2111,2167,2171,

%T 2311,2331,2391,2395,2411,2475,2731,7527,7599,8143,8159,8303,8359,

%U 8379,8383,8439,8443,8663,8667,8683,9159,9223,9243,9323,9559,9563

%N Monotonic ordering of set S generated by these rules: if x and y are in S then 5xy-x-y is in S, and 1 is in S.

%t start = {1}; f[x_, y_] := 5 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 100000 &]];

%t t = NestList[b, start, 12][[-1]] (* A192528 *)

%t Table[t[[i]] - t[[i - 1]], {i, 2, Length[t]}] (* differences *)

%Y Cf. A192476.

%K nonn

%O 1,2

%A _Clark Kimberling_, Jul 03 2011