What are the PARI/GP alternatives to contfrac() ?

[Rainer Rosenthal]

Max Alekseyev wrote:

> On the other hand, one of possible irregular continued fractions for Pi is:
> http://upload.wikimedia.org/math/a/c/3/ac36499053d43d4ecd46a4624c0a05b2.png
> where the sequence of partial denominators is simply all odd positive
> integers, hence, *this sequence* (not the form of ontinued fractions)
> is somewhat regular.

I feel like saying "spectarecular" ... This is a wonderful
way of writing Pi. I googled back to wikipedia and found
the link in
http://en.wikipedia.org/wiki/Continued_fraction#Continued_fraction_expansions_of_.CF.80

Do you know who found this expansion? Or could somebody else
please tell me? Looks like Ramanujan ... amazing!

Greetings and a Happy New Year,
Rainer Rosenthal
r.rosenthal at web.de