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A192537 Monotonic ordering of set S generated by these rules:  if x and y are in S then x^2+y^2-xy/2 is in S, and 2 is in S. 3
2, 6, 34, 54, 1090, 1126, 1734, 2790, 2866, 3154, 4374, 1161586, 1170726, 1184866, 1187014, 1240390, 1249890, 1264534, 1266754, 1782150, 1842306, 1901814, 2962854, 2978434, 3001590, 3005026, 3249826, 3298390 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

See A192476.

LINKS

Table of n, a(n) for n=1..28.

MATHEMATICA

start = {2}; f[x_, y_] := x^2 + y^2 - x*y/2

b[x_] :=

  Block[{w = x},

   Select[Union[

     Flatten[AppendTo[w,

       Table[f[w[[i]], w[[j]]], {i, 1, Length[w]}, {j, 1, i}]]]], # <

      4000000 &]];

t = FixedPoint[b, start] (* A192537 *)

t/2 (* A192538 *)

CROSSREFS

Cf. A192476, A192538.

Sequence in context: A064940 A105142 A227306 * A026966 A026976 A026951

Adjacent sequences:  A192534 A192535 A192536 * A192538 A192539 A192540

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jul 04 2011

STATUS

approved

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Last modified July 24 05:05 EDT 2021. Contains 346273 sequences. (Running on oeis4.)