[seqfan] Re: A070543 (counting k-dimensional isotropic subspaces)

[Neil Sloane]

This is all classical geometry, and everything is known. I did not check
that particular formula, but it looks right. It is a theorem not a
conjecture. There are many references in my book on coding theory with
MacWilliams.  I corrected the offset and added a Maple program.
Best regards
Neil

Neil J. A. Sloane, President, OEIS Foundation.
11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
Phone: 732 828 6098; home page: http://NeilSloane.com
Email: njasloane at gmail.com



On Wed, Aug 21, 2019 at 9:21 AM Peter Munn <techsubs at pearceneptune.co.uk>
wrote:

> Hello seqfans,
>
> I've been working on a contribution to A141419, and in doing this have
> spotted a link to A070543. So I am preparing a formula to express this
> link derived from the one for T(n, k) in A070543.
>
> This led me to notice that either the A070543 formula is wrong or
> A070543's offset is, and from the Baez link it is the offset.
>
> In reading Baez's page, I notice he says, effectively in respect of
> A070543, "I leave it as an easy puzzle to figure out the pattern, and a
> harder puzzle to prove it's true." Not being well-versed in this field,
> I'm not sure what he means by "harder" and am left wondering whether the
> formula (which I am using to derive my new formula) is conjecture or
> truth.
>
> Can anyone enlighten?
>
> Best Regards,
>
> Peter
>
>
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