OFFSET
1,1
COMMENTS
See A195500 for a discussion and references.
FORMULA
Empirical g.f.: x*(3*x^6+8*x^5+120*x^4-134*x^3+120*x^2+8*x+3) / (x^9-257*x^6-257*x^3+1). - Colin Barker, Jun 04 2015
MATHEMATICA
r = 7/4; z = 26;
p[{f_, n_}] := (#1[[2]]/#1[[
1]] &)[({2 #1[[1]] #1[[2]], #1[[1]]^2 - #1[[
2]]^2} &)[({Numerator[#1], Denominator[#1]} &)[
Array[FromContinuedFraction[
ContinuedFraction[(#1 + Sqrt[1 + #1^2] &)[f], #1]] &, {n}]]]];
{a, b} = ({Denominator[#1], Numerator[#1]} &)[
Sqrt[a^2 + b^2] (* A195570 *)
(* Peter J. C. Moses, Sep 02 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Sep 21 2011
STATUS
approved