A192648 Monotonic ordering of set S generated by these rules: if x and y are in S and x^2-y^2>0 then x^2-y^2 is in S, and 2 and 3 are in S.

2, 3, 5, 16, 21, 185, 231, 247, 252, 416, 432, 437, 2495, 4345, 7648, 10143, 13568, 17913, 19136, 26784, 29279, 33784, 33969, 34200, 34216, 34221, 52920, 53105, 53336, 53352, 53357, 60568, 60753, 60984, 61000, 61005, 63063, 63248, 63479

Offset

1,1

Comments

See A192645.

Links

Ivan Neretin, Table of n, a(n) for n = 1..10000

Mathematica

start = {2, 3};
f[x_, y_] := If[MemberQ[Range[1, 150000], x^2 - y^2], x^2 - 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}]]]], # <
      150000 &]];
t = FixedPoint[b, start]  (* A192648 *)

Crossrefs

Cf. A192476, A192646.

Sequence in context: A248827 A273525 A274336 * A219339 A360695 A048112

Adjacent sequences: A192645 A192646 A192647 * A192649 A192650 A192651

Keyword

nonn

Author

Clark Kimberling, Jul 06 2011

Status

approved