A192650 First differences of A192649.

1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 4, 3, 7, 1, 1, 6, 1, 5, 3, 7, 1, 4, 3, 1, 1, 7, 5, 2, 1, 1, 14, 16, 1, 7, 8, 1, 1, 6, 5, 3, 1, 1, 7, 7, 2, 14, 1, 9, 7, 8, 7, 1, 1, 7, 5, 2, 1, 1, 6, 9, 7, 5, 3, 1, 1, 7, 9, 6, 1, 5, 2, 1, 1, 8, 15, 8, 31, 9, 9, 8, 8, 7, 23, 1, 1, 8, 7, 5, 3, 7, 1, 1, 15, 7, 24, 1

Offset

1,5

Comments

Are there infinitely many pairs 1,1?

Links

Table of n, a(n) for n=1..97.

Mathematica

start = {1, 2, 4};
f[x_, y_] := If[MemberQ[Range[1, 700], 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}]]]], # <
      700 &]];
t = FixedPoint[b, start]  (* A192649 *)
Differences[t] (* A192650 *)

Crossrefs

Cf. A192649, A192646.

Sequence in context: A335174 A082905 A141524 * A178059 A116188 A318274

Adjacent sequences: A192647 A192648 A192649 * A192651 A192652 A192653

Keyword

nonn

Author

Clark Kimberling, Jul 06 2011

Status

approved