Re: recurrence-guess.gp

[Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>]

On Sun, Feb 21, 2016 at 06:57:52PM +1100, Kevin Ryde wrote:
> I tried a bit of code to find a linear recurrence or gf for given values.
> I've had a few forms for quite a while but this is the first presentable
> one :)
> 
>     http://user42.tuxfamily.org/pari-recurrence-guess/index.html
> 
> Others have done the same, and the guts is a simple matsolve(), the only
> difference here is some printing.  I use it to see how something
> complicated comes out, and if good then a gf or power expression to copy
> into code or text.  The look is slightly personal preference, but might
> give another perspective.

Instead of matsolve,

? recurrence_guess(v)=denominator(bestapprPade(Ser(v)));
? recurrence_guess([1, 3, 9, 25, 65, 161, 385, 897, 2049, 4609])
%7 = -4*x^3+8*x^2-5*x+1

Cheers,
Bill.