# [seqfan] Re: seq needed of (0,+-1) matrices

Ron Hardin rhhardin at att.net
Thu Jan 19 22:51:19 CET 2012

```No problem, the machine does the work
mine continues to term 8
1 3 27 293 3605 52327 899311 18019017

a ninth term possible but doubtful

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

----- Original Message ----
> From: N. J. A. Sloane <njas at research.att.com>
> To: seqfan at list.seqfan.eu
> Cc: rhhardin at mindspring.com; njas at research.att.com
> Sent: Thu, January 19, 2012 4:41:46 PM
> Subject: [seqfan] Re: seq needed of (0,+-1) matrices
>
> Robert Israel found the explanation!
> I was using
>
>star:=A[w,x]*A[y,z]+A[w,y]*A[x,z]+A[w,z]*A[x,y]-A[w,x]*A[w,y]*A[w,z]*A[x,y]*A[x,z]*A[y,z];
>;
>
> and  got a(4) = 125, agreeing with Max A.,
>
> but when I corrected this to
>
>star:=A[w,x]*A[y,z]+A[w,y]*A[z,x]+A[w,z]*A[x,y]-A[w,x]*A[w,y]*A[w,z]*A[x,y]*A[x,z]*A[y,z];
>;
>
> I  get a(4) = 293, agreeing with rhh.
>
> So it does look like we get two  sequences!
>
> The second version is the one in Wesp's paper (although
> he  does not give any numerical values)
>
> Robert, thanks for straightening this  out!
>
> I will add the other version - it will be A204821 (and
> A204809  is the other  version)
>
> Neil
>
>
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>

```