[seqfan] Re: Counting binary matrices - can these really be new?

[Ron Hardin]

I get 0 1 1 2 5 13 42 155 636 2889 14321 76834 for A229161 (offset 1)
matching its 1, 1, 2, 5, 13, 42, 155, 636, 2889, 14321 (offset 2)
using the definition two 1's in every row and column and
rows and columns in lexicographically nondecreasing order.

Maybe another term or so to come.


 
rhhardin at mindspring.com
rhhardin at att.net (either)



>________________________________
> From: Neil Sloane <njasloane at gmail.com>
>To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu> 
>Sent: Sunday, September 15, 2013 10:46 PM
>Subject: [seqfan] Counting binary matrices - can these really be new?
> 
>
>Dear Seq Fans and especially Ron Hardin.
>I just added A229161-A229164 based on this paper:
>K. Yordzhev, <a href="http://arXiv.org/abs/1305.6790">Fibonacci sequence
>related to a combinatorial problem on binary matrices</a>, arXiv preprint
>arXiv:1305.6790, 2013
>
>It looks like he is counting binary nXn matrices with a fixed number of 1's
>in each row and column, up to permutations of the rows and columns . As he
>says, these were not in the OEIS. Hard to believe, so maybe I have
>misunderstood the definition. They need more terms.
>
>Someone will probably extend these very quickly, so check
>the entries before spending any time on this.
>Neil
>
><njasloane at gmail.com>
>
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