[seqfan] Re: A009927 (was Re: "more" keyword)

Neil Sloane njasloane at gmail.com
Fri Dec 18 19:27:05 CET 2015


> I see that Neil has added "Needs a b-file" to A000927 and its partial sums
A265038.
> The gfun package suggests a G.f. for A000927:

s/000927/009927/g

It would be very nice to have a proof for the g.f.

> This does look like G.f.'s for other sequences of this type.

Yes, but I'm not sure if any of them have been proved.  Looking back over
20 years to this paper:

R. W. Grosse-Kunstleve, G. O. Brunner and N. J. A. Sloane, Algebraic
Description of Coordination Sequences and Exact Topological Densities for
Zeolites <http://neilsloane.com/doc/ac96cs/>, Acta Cryst., A52 (1996), pp.
879-889,

I can't remember now if the g.f.s given there were empirical or if we
proved that they were correct. For a chemistry journal the distinction
didn't matter ....


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 Fri, Dec 18, 2015 at 12:51 PM, <israel at math.ubc.ca> wrote:

> I see that Neil has added "Needs a b-file" to A000927 and its partial sums
> A265038.
> The gfun package suggests a G.f. for A000927:
>
>
> -(12*x^14+8*x^13-7*x^12+16*x^11+51*x^10+182*x^9+327*x^8+418*x^7+450*x^6+350*x^5+243*x^4+130*x^3+51*x^2+12*x+1)/(x^12+x^10-2*x^9-x^8-2*x^7+2*x^5+x^4+2*x^3-x^2-1)
>
> The denominator factors as
> (x+1)*(x^2+1)^2*(x^2+x+1)^2*(x-1)^3
>
> This does look like G.f.'s for other sequences of this type. Can someone
> confirm that this G.f. is correct? Otherwise I'll just call this an
> "empirical" g.f.
>
> Cheers,
> Robert
>
>
>
> On Dec 17 2015, Neil Sloane wrote:
>
> well, no.  "more" officially means we need more terms to fill out three
>> punched cards
>>
>> we really need a new keyword "bmore" (or "bore" if
>> we want a 4-letter word)
>>
>> but we aren't adding new keywords these days.
>>
>> I suggest a simple comment line: "Needs a b-file"
>>
>> This is something I've thought of myself many times
>>
>> If we always use the same wording "Needs a b-file" then after a while
>> folks will be able to do a search for it when they want to help
>>
>> 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 Thu, Dec 17, 2015 at 8:28 PM, Frank Adams-Watters <
>> franktaw at netscape.net> wrote:
>>
>> Is it legitimate to use the "more" keyword when there are sufficient
>>> terms in the entry, but more terms are wanted for a b-file?
>>>
>>> Franklin T. Adams-Watters
>>>
>>>
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>>>
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>>
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