cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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.

Original entry on oeis.org

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

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Author

Clark Kimberling, Jul 04 2011

Keywords

Comments

See A192476.

Crossrefs

Programs

  • 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 *)