[seqfan] Re: A_k and RMPN

Donovan Johnson donovan.johnson at yahoo.com
Thu Dec 12 21:55:01 CET 2013


Here is the smallest solution for k=5:

[53542288800, 59509850400, 59999219280, 60074174160, 61695597600]
common sigma value: 294821130240

I also found seven more solutions with sigma values < 5*10^11.
I'm checking now if these are the eight smallest solutions (program should finish in about 15 hours).

Donovan






On Thursday, December 12, 2013 12:49 PM, M. F. Hasler <seqfan at hasler.fr> wrote:
 
On Mon, Dec 9, 2013 at 1:52 AM, Charles Greathouse <
charles.greathouse at case.edu> wrote:

> I notice that the 2-tuples are already in the OEIS as A206708. Perhaps an
> index entry would also be warranted?
>
>

I agree. Found this (& followings) :

A125490
Amicable triples: numbers such that sigma(x) = sigma(y) = sigma(z) = x+y+z,
x<y<z. Sequence gives x numbers.

Maybe we should systematically push back to "editing" proposed sequences
when it is obvious that the author was too lazy to do a little (or longer)
search) to link to some relevant other sequences and in particular link
"back" to some more elementary sequences.
("4-tuples" should link to 3-tuples which should link to amicable pairs, of
course the upward links should be there, too.)

I'm adding Michel's values as https://oeis.org/draft/A233553 .

Regards,
Maximilian


Charles Greathouse
> Analyst/Programmer
> Case Western Reserve University
>
>
> On Sun, Dec 8, 2013 at 8:04 PM, <zbi74583.boat at orange.zero.jp> wrote:
>
> >     Hi,Seqfans
> >
> >     I am the first mathematician who computed Amicable k-ple for k=4,
> k=5.
> >
> >    http://mathworld.wolfram.com/AmicableQuadruple.html
> >
> >    http://list.seqfan.eu/pipermail/seqfan/2008-November/000217.html
> >
> >     Still for 5 < k, no Amicable k-ple is known.
> >
> >     OEIS has Amicable 4-ple. A036371-A036474
> >
> >     But it does not yet have A_5.
> >     I think OEIS should have it.
> >
> >     Could anyone compute the first several terms?
> >
>
>



-- 
Maximilian


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