[seqfan] Re: How many ways to dissect a square into 4 congruent pieces

[Neil Sloane]

I have now updated the entry for A003213 with a copy of Tom Parkin's
11-page letter to Fred Gruenberger, giving more information about his
calculations. I hope that this will explain why his results are different
from Don's and Giovanni's.  In any case, could you (Giovanni, perhaps)
create
a new entry for your results (and tell me the A-number)?


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, May 13, 2015 at 12:19 PM, Neil Sloane <njasloane at gmail.com> wrote:

> Well, don't change the values in A003213, even if they seem to be wrong.
> The OEIS policy is to include published sequences that are wrong along
> with a pointer to the correct entry.
>
> So, please, create a new entry for the correct terms (once everyone agrees
> on what the correct values are), and I will edit A003213 to point to it.
>
> I must say I'm very surprised that Tom Parkin's entries are wrong - he was
> normally very reliable, and an expert programmer, and famous for finding a
> counter-example to a conjecture of Euler.  Also a vice-president at CDC.
> Here are some references in the OEIS to his work:
>
> %D A000104 T. R. Parkin, L. J. Lander and D. R. Parkin, "Polyomino
> enumeration results," SIAM Fall Meeting, Santa Barbara, California, 1967.
>
> %H A000230 L. J. Lander and T. R. Parkin, <a href="
> http://dx.doi.org/10.1090/S0025-5718-1967-0230677-4">On the first
> appearance of prime differences</a>, Math. Comp., 21 (1967), 483-488.
>
> %H A001560 T. R. Parkin and D. Shanks, <a href="
> http://www.jstor.org/stable/2003251">On the distribution of parity in the
> partition function</a>, Math. Comp., 21 (1967), 466-480.
>
> %H A039664 L. J. Lander, T. R. Parkin and J. L. Selfridge, <a href="
> http://links.jstor.org/sici?sici=0025-5718%28196707%2921%3A99%3C446%3AASOESO%3E2.0.CO%3B2-7">A
> survey of equal sums of like powers</a>, Math. Comp. vol. 21 no. 99, 1967,
> pp. 446-459, Table 1.
>
> %D A048242 Parkin, Thomas R.; Lander, Leon J.; Abundant numbers, Aerospace
> Corporation, Los Angeles, 1964, 119 unnumbered pages. Copy deposited in UMT
> file.
>
> %H A089180 L. J. Lander and T. R. Parkin, <a href="
> http://dx.doi.org/10.1090/S0025-5718-1967-0222008-0">Consecutive primes
> in arithmetic progression</a>, Math. Comp. vol 21 no 99 (1967) p 489.
>
> %H A134341 L. J. Lander and T. R. Parkin, <a href="
> http://dx.doi.org/10.1090/S0002-9904-1966-11654-3">Counterexample to
> Euler's conjecture on sums of like powers</a>, Bull. Amer. Math. Soc. 72
> (6) (1966), p. 1079.
>
>
> Is it possible that he interpreted the problem in a different way?  I do
> have several more pages about his calculations that I will scan in and
> attach to A003213, in case that will help explain what he was doinmg.  I
> will try to do that later today.
>
> 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, May 13, 2015 at 12:01 PM, Giovanni Resta <g.resta at iit.cnr.it>
> wrote:
>
>> I also got a(8) = 6371333036059.
>>
>> Later on, if nobody objects, I could edit A003213 accordingly.
>>
>> Giovanni
>>
>>
>>
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>