[seqfan] Re: offsets of constants

Charles Greathouse charles.greathouse at case.edu
Fri Aug 21 21:49:30 CEST 2009


I'm not entirely sure that the b-file format is best for constants.
First, it's hard to read (by computers as well as people).  Why are we
converting to a format that's not easy to use?  Pretty much every
program out there natively reads and writes to one or both of
123456789
or
1234\
5678\
9

Second, it's space-inefficient: it takes 3n + A058183(n) bytes on
*nix-based systems, and 4n + A058183(n) bytes on Windows, to store the
digits through n.  Granted, that's only 67 kB per sequence (or 770 kB
for constant important enough to merit 100,000 digits).

Of course if there are good reasons I'm missing, please bring them up.
 Before someone mentions it, I don't think that
http://www.research.att.com/~njas/sequences/table?a=796&fmt=5
is particularly compelling.

But whatever is decided, I'd be happy to pitch in on the conversion
effort.  Maybe someone can compile a list and split up the work so
there's no duplication?

Charles Greathouse
Analyst/Programmer
Case Western Reserve University

On Fri, Aug 21, 2009 at 2:02 PM, <franktaw at netscape.net> wrote:
> Hundreds.  A search for 'keyword:cons link:"table of"' finds 388
> matches.  I think this finds exactly the b-files for these cases.  (For
> pi (A000796), there's another link to a "table of contents ...", but
> there is also a b-file.)
>
> (Curiously, the link for e (A001113) claims that the digits are labeled
>  from zero, as I would have them; but the b-file actually labels them
> from one.)
>
> I'll admit I hadn't considered this aspect.  You have to change not
> only the b-file, but also the reference to it.
>
> Franklin T. Adams-Watters
>
> -----Original Message-----
> From: N. J. A. Sloane <njas at research.att.com>
>
> Franklin's proposed change is probably a good idea.
> And it would be relatively easy to change all
> the %O lines in the file which contains the database.
>
> However, the difficult part would be to change
> all thye b-files, of which ere are hundreds (even thousand)
> for these constants.
>
> Neil
>
>
>
>
>
>
>
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>
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