# [seqfan] Re: Integer Sequence Analysis in Mathematica 7

Maximilian Hasler maximilian.hasler at gmail.com
Sat Nov 22 02:54:35 CET 2008

```Well, for 30 given values there's always a polynomial of degree 29
that fits *exactly* through these points, but in general not through
the 31st point...
Did you try to ask for the "exact" solution for 15 points and then to
check the 16th point ?
(NB: I don't pretend that what you copied is a polynomial !)

But I agree that HypergeometricPFQ is a nice "encoding" of the answer.
Well, actually A001609(n) is the most concise and most informative way
to code that function.

Maximilian

On Fri, Nov 21, 2008 at 9:45 PM, Alexander Povolotsky
<apovolot at gmail.com> wrote:
> Dear Maximilian,
>
> I was not talking ggf, I meant closed form analytical formula
>
> For example PURRS (The Parma University's Recurrence Relation Solver)
> http://www.cs.unipr.it/purrs/  yields the following:
>
> Exact solution for x(n) = x(-1+n)+x(-3+n)
> x(n) = 1/2*(I*(29/54+1/18*sqrt(93))^(1/3)*sqrt(3)-I*sqrt(3)*(29/54-1/18*sqrt(93))^
> ...*(29/54-1/18*sqrt(93))^(1/3))^n*x(0)
> for each n >= 0
>
> But when trying to add initial conditions for exact solution PURRS demo gives
> PURRS Demo Error
> memory limit exceeded
>

```