[seqfan] Re: Divisor partitions

Robert Dougherty-Bliss robert.w.bliss at gmail.com
Fri Mar 27 02:11:47 CET 2020


Don,

>     A067824(N) is the number of divisor partitions with maximum value N.

Can you elaborate on this? Divisor partitions of which set?
For example, what are the A067824(4) = 4 divisor partitions with maximum
value 4?

I think that A067824(N) = number of subsets of [N] which contain N and
satisfy
the divisor pair condition.

With this I get:

    {4}, {2, 4}, {1, 2, 4}, {1, 4}.

Robert


On Thu, Mar 26, 2020 at 7:11 PM Don Reble via SeqFan <seqfan at list.seqfan.eu>
wrote:

> > Let a(n) be the total number of divisor partitions of [n] = {1, 2, ...,
> n}
> >   1, 2, 3, 7, 9, 25, 30, 78, 138, 342, 386, 1307
>
>     I get
>     1 2 3 7 9 25 30 78 138 342 386 1307 1448 3406 6818 18907 20478 65901
>     70781 213704 397874 885118 939377 3624495 5034048 11032794 20966732
>     59398560 62307000 225641196 235937708 682530590 1183122260
>     2540294162 4026533578 15943721982 16555409210 35301649136
>
> > Does something related already appear in the OEIS?
>
>     A067824(N) is the number of divisor partitions with maximum value N.
>
> --
> Don Reble  djr at nk.ca
>
>
> --
> Seqfan Mailing list - http://list.seqfan.eu/
>



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