[seqfan] Re: List of sequences with linear recurs. and o.g.f. missing
arndt at jjj.de
Fri Apr 16 10:56:15 CEST 2010
Firstly I suggest a keyword 'per' indicating PERiodicty
(and another one 'nper' for eveNtually PERiodic seqs).
It will be very helpful with searching.
Earlier I suggested a keyword 'lrec' indicating that the seq
(OGF) is a rational function (i.e. there is a Linear RECurrence
(with constant coefficients)).
But this was declined... *sob!*
Keywords like the above will be crucial for searching in
more and more seqs. Example: when searching for a string
of symbols generated as fixed points of a morphism I'd
like to exclude those with 'lrec'.
* Richard Mathar <mathar at strw.leidenuniv.nl> [Apr 16. 2010 09:01]:
> There is a list of sequences which are periodic (because they
> are defined by b^n mod m with constant base b and constant remainder m) and
> are not yet showing the formulas of the linear recurrence and the associated
> ordinary generating function:
A mechanical task:
? \r ggf.gpi
? ggf([1, 5, 7, 8, 4, 2, 1, 5, 7, 8, 4, 2, 1, 5, 7, 8, 4, 2, 1, 5, 7, 8, 4, 2, 1, 5, 7])
(2*x^3 + 2*x^2 + 4*x + 1)/(-x^4 + x^3 - x + 1)
Suggest automated approach after undeclining 'lrec'.
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