[Help-gsl] Generating the coefficients in lanczos_7_c

[Fredrik Johansson]

Greetings,

I have written an implementation of the Gamma function for a personal
project, based on code from the lngamma_lanczos_complex function in
GSL.

I am now wondering if anyone could provide an explicit formula for the
calculation used by lngamma_lanczos_complex. In particular, I am
interested in the derivation for the coefficients in the table
lanczos_7_c, as I would like to generate them instead of just copying
the number literals from the GSL source.

Presumably the information I need can be obtained from the cited SIAM
journal article, but it is not easily available for me from where I
live now.

Assistance would be much appreciated.

Fredrik