[seqfan] Re: Another surprising omission from OEIS

Michael Porter ic_designer at verizon.net
Thu Nov 12 09:24:55 CET 2009

A more "liberal" search engine sounds really hard to do, but one thing that might be really easy to do is add a paragraph to the "No sequence found" page.  It could suggest removing the first few terms and trying again, so instead of searching for 0, 1, 3, 9, 42, 206, 1352, search for 3, 9, 42, 206, 1352.

- Michael

--- On Wed, 11/11/09, Chris Starling <chaosorder4 at gmail.com> wrote:

From: Chris Starling <chaosorder4 at gmail.com>
Subject: [seqfan] Re: Another surprising omission from OEIS
To: "Sequence Fanatics Discussion list" <seqfan at list.seqfan.eu>
Date: Wednesday, November 11, 2009, 1:30 PM

I just experimented by searching for some of my own sequences, with and
without including a fake zero term.  Including the fake zero did indeed
throw a legitimate answer right out of the results.  I don't mean off to the
second page, but completely out.

I tried to think philosophically, what does information want to do?  It
wants to be found, copied, known about.

In that light, I would say do whatever it takes to allow the sequence to be
found.  Especially from the point of view of a cross-disciplinary search.
Most math-oriented folks would know in advance whether or not to include
zero, but what about an historian or an artist, or even another type of

My vote is either A) have a more liberal search program that won't give
hysterical weight to a single searched term, or B) submit 2 sequences, one
with the zero and one without.  Of course option B will result in more
duplication of term strings, but that is exactly the kind of crosslinking
the internet is for, and it is better than an historian just not quite
finding out, maybe, that the chaotic plot of available timber lengths used
in cathedrals matches the digits of the trinary representation of the root
of pi.

A non-math person not finding that tidbit would be downright sad, whereas
duplicated sequence terms might be merely annoying, and usually not even,
although I would feel a sense of duty to ask Neil to weigh in on that last

On Wed, Nov 11, 2009 at 8:52 AM, <hv at crypt.org> wrote:

> Andrew Weimholt <andrew.weimholt at gmail.com> wrote:
> :I'm still somewhat neutral on whether to include 0, and would like to
> :hear some other thoughts on this question.
> There are two distinct sequences, identical in all respects except for
> inclusion of zero.
> Which is "more natural"? Depends how you're looking at it - from an
> algebraic point of view, there is no reason to exclude x=0; from
> a "repunit" point of view there is (since it appeals to "how we write
> numbers" rather than to intrinsic mathematical properties).
> So I'd include zero to ensure that someone foolish enough to include it
> in their search terms would find the sequence, and add a comment to clarify
> the nature of the two sequences represented.
> Hugo
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