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.

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

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