close form solution for A136010 (per PURRS http://www.cs.unipr.it/purrs/)

[Jaap Spies]

Joerg Arndt wrote:
> For those who want to refresh the basics about computations of
> recurrences using matrix powers or (better!) powers modulo the
> characteristic polynomial, Binet forms, recurrences for subsequences,
> Binet forms etc., I dare to point to pp.655-665 of the text
> http://www.jjj.de/fxt/#fxtbook
> The stuff is written for programmers and hopefully accessible
> for people without strong background in math.
> 
> Ralf Stephan's ggf (Guess Generating Function) script is
> always handy, a copy is here:
> http://www.jjj.de/pari/ggf.inc.gp
> 
> cheers,   jj  (feeling a bit like a spammer now)
> 

Good work! I would love to have this in a Sage version!
As Sage is Python in a way, and Python is executable
pseudocode so to speak.
Moreover you can run pari/gp code from within Sage.

Jaap