OFFSET
1,1
REFERENCES
David W. Cantrell, A new convergent expansion for the gamma function, sci.math.num-analysis, Nov 05, 2001: http://groups.google.com/group/sci.math.num-analysis/msg/521fa1a6fb98a300
LINKS
David W. Cantrell, Table of n, a(n) for n = 1..18
EXAMPLE
For Re(z) > 0, Gamma(z + 1/2) = sqrt(2*pi)*(z/e)^z / [1 + 1/( 24*z - 1/2 + CF(z) )]
where continued fraction CF(z) = 1/(c_1*z + 1/(c_2*z + 1/(c_3*z + ...))) with c_1 = 1440/2021, c_2 = 686186088/125896643, c_3 = 1521596612992267104/4596084813365743279, ...
MATHEMATICA
i = 5; s = 1 - Simplify[Normal[Series[Gamma[z + 1/2], {z, Infinity, 2*(i + 1)}]]/((z/E)^z*Sqrt[2*Pi]), z > 0]; s = Series[1/s, {z, Infinity, 2*i}]; i = i - 1; s = Series[1/(s - (24*z + 1/2)), {z, Infinity, 2*i}]; CoeffList = {}; While[i >= 0, c = First[s[[3]]]; AppendTo[CoeffList, c]; s = Series[1/(s - c*z), {z, Infinity, 2*i}]; i = i - 1]; Numerator[CoeffList]
CROSSREFS
KEYWORD
frac,nonn
AUTHOR
David W. Cantrell (DWCantrell(AT)sigmaxi.net), May 18 2006
STATUS
approved