[seqfan] Re: Divisibilty sequences

Joerg Arndt arndt at jjj.de
Sun Mar 29 06:52:58 CEST 2009


* Maximilian Hasler <maximilian.hasler at gmail.com> [Mar 29. 2009 15:40]:
> IMHO the property of being division sequence also merits a keyword ("divs" ?)

I strongly support this.

Also we might want to have a keyword which indicates
that the sequence has only finitely many values,
useful e.g. with seqs that are generated by morphisms.

Keywords make searching more powerful!


> 
> Maximilian
> PS: Great work from RKG. 2 more relations:
> A106328 = 3*A001109
> A005319 = 4*A001109
> 
> 
> On Sat, Mar 28, 2009 at 3:33 PM, Richard Guy <rkg at cpsc.ucalgary.ca> wrote:
> > Towards a multiplicative theory of divisibility sequences.
> >
> > A001542 = 2 * (A001109)
> > A003690 = 3 * (A004254)^2
> > A003696 = (A001353) * (b=14,c=68)  latter not in OEIS?
> > A003733 = 5 * (A143699)^2
> > A003739 = 5 * (A001906) * (A006238)
> > A003745 = 3 * 5^2 * (A004254) * (A004187)^3
> > A003751 = 5^3 * (A004187)^4
> > A003753 = 2^2 * (A001109) * (A001353)^2
> >         = 2 * (A001542) * (A001353)^2
> > A003755 = (A001109) * (A001906)^2
> > A003761 = (A001906) * (A004254) * (A001109)
> > A003767 = 2^3 * (A001353) * (A001109)^2
> > A003773 = 2 * (A001542)^3 = 2^4 * (A001109)^3
> > A092136 = (A004187) * (A001906)^3
> >
> > E&OE     R,
> >
> >




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