A (Somewhat) Interesting Recursion

[hv at crypt.org]

straightforward duplicates:
	-Andrew Plewe-
Return-Path: <apache at im.bas-net.by>
X-Ids: 166
Message-ID: <1177107496.46293c28aa689 at im.bas-net.by>
Date: Sat, 21 Apr 2007 01:18:16 +0300
From: liskov at im.bas-net.by
To: Simon Plouffe <simon.plouffe at gmail.com>
Cc: seqfan at ext.jussieu.fr, Maximilian Hasler <maximilian.hasler at gmail.com>
Subject: Re: Identification of fractional sequences
References: <4628848D.ACB87091 at im.bas-net.by> <33a322bc0704200643q79fe6891lb5927a49907565ca at mail.gmail.com>
In-Reply-To: <33a322bc0704200643q79fe6891lb5927a49907565ca at mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=windows-1251
Content-Transfer-Encoding: 8bit
User-Agent: Internet Messaging Program (IMP) 3.2.2
Sender: Apache <apache at im.bas-net.by>
X-Greylist: Delayed for 01:17:45 by milter-greylist-2.0.2 (shiva.jussieu.fr [134.157.0.166]); Sat, 21 Apr 2007 01:36:08 +0200 (CEST)
X-Virus-Scanned: ClamAV 0.88.7/3141/Fri Apr 20 22:23:13 2007 on shiva.jussieu.fr
X-Virus-Status: Clean
X-j-chkmail-Score: MSGID : 46294E67.000 on shiva.jussieu.fr : j-chkmail score : X : 0/50 0 0.541 -> 1
X-Miltered: at shiva.jussieu.fr with ID 46294E67.000 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)!

Thanks! But will this work if the denominators and numerators
are in reality more complicated than factorials but still
quite familiar sequences whose corresponding elements are
sometimes simultaneously even or/and divisible by 3, etc.?

Valery

Simon Plouffe <simon.plouffe at gmail.com> wrote:

> This is a classic case, (if I may),
>
> you should use GFUN (maple) or the equivalent
> on Mathematica, with these tools you can
> manipulate sequences as if they were exponential
> or ordinary gen. functions and from there easily
> identify any possible sequence.
>
> the command are <listtoseries> , etc.
>
> type ?gfun on a maple session
>
> simon plouffe
>





Valery,  you said:

> Thanks! But will this work if the denominators and numerators
> are in reality more complicated than factorials but still
> quite familiar sequences whose corresponding elements are
> sometimes simultaneously even or/and divisible by 3, etc.?

My answer: normalize the denominators so that they
are some recognziable sequence:

That is, write f(n) = a(n)/b(n), where you understand b(n).

Now concentrate on a(n), which you
can look up in the OEIS, send to superseeker, etc.

Of course they will be several choices for the denominator

Neil