Kevin Ryde on Sun, 15 May 2016 10:13:41 +0200


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Re: periodic generating function 

Ralf Stephan <gtrwst9@gmail.com> writes:
>
> ? poliscyclo(1+x+x^2)
> %1 = 3

Ah yep beaut.  I thought it had to be one of the cyclotomic thingies,
without knowing which.

> ? factor(1-4*x^12)
> %3 =
> [2*x^6 - 1 1]
> [2*x^6 + 1 1]
>
> ? poliscyclo(2*x^6 + 1)
> %4 = 0

Alas yes that's the kind of one I want.  (The 4 becomes values like
4^floor(n/12) and I then apply numerator terms, reduce to 2^floor(n/6)
with adjustment, ...)