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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
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 (list; graph; refs; listen; history; text; internal format)
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 A048112 A001042

Adjacent sequences:  A192645 A192646 A192647 * A192649 A192650 A192651

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jul 06 2011

STATUS

approved

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Last modified February 20 15:00 EST 2019. Contains 320327 sequences. (Running on oeis4.)