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%I #5 Mar 30 2012 18:57:34
%S 3,4,6,8,9,12,13,16,18,19,24,26,27,28,32,36,38,39,40,42,48,52,54,56,
%T 57,58,60,63,64,72,76,78,80,81,84,85,87,90,94,96,104,108,112,114,116,
%U 117,120,121,123,126,127,128,130,135,141,144,152,156,160,162,168,169
%N Monotonic ordering of set S generated by these rules: if x and y are in S then floor(x*y/2) is in S, and 3 is in S.
%t start = {3}; f[x_, y_] := Floor[x*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 400 &]];
%t t = NestList[b, start, 12][[-1]] (* A192519 *)
%t Table[t[[i]] - t[[i - 1]], {i, 2, Length[t]}]
%Y Cf. A192476.
%K nonn
%O 1,1
%A _Clark Kimberling_, Jul 03 2011
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