[seqfan] Re: Sum divides concatenation

zak seidov zakseidov at yahoo.com
Tue Sep 29 20:49:45 CEST 2009

```In this version we have:
1,2,6,0,19260,231228,308304,42920,82996,124494,1037450,456478,1244940,...

Zak

--- On Tue, 9/29/09, zak seidov <zakseidov at yahoo.com> wrote:

> From: zak seidov <zakseidov at yahoo.com>
> Subject: [seqfan] Re: Sum divides concatenation
> To: "seqfaneu" <seqfan at seqfan.eu>
> Date: Tuesday, September 29, 2009, 2:06 PM
>
> May be you mean a(n)>a(n-1)?
> Otherwise,  why not a(4)=0:
> 1+2+6+0=9 and 9|1260?
> Zak
>
> --- On Tue, 9/29/09, John W. Layman <layman at math.vt.edu>
> wrote:
>
> > From: John W. Layman <layman at math.vt.edu>
> > Subject: [seqfan] Re: Sum divides concatenation
> > To: "Sequence Fanatics Discussion list" <seqfan at list.seqfan.eu>
> > Cc: Eric.Angelini at kntv.be
> > Date: Tuesday, September 29, 2009, 12:28 PM
> > Eric Angelini wrote:
> > > Hello SeqFans,
> > > I don't know how to find more terms -- thus I
> don't
> > know
> > > if this is old hat in Neil's database:
> > >
> > > 1, 2, 6, ...
> > >
> > > The sum of the first n integers divides the
> > concatanion of
> > > the first n integers; always prolong the seq with
> the
> > smal-
> > > lest _natural_ number not yet used:
> > >
> > > 1 divides 1  --> HIT
> > > 1+2   (=3) divides 12 --> HIT
> > > 1+2+3 (=6) does not divide 123
> > > 1+2+4 (=7) does not divide 124
> > > 1+2+5 (=8) does not divide 125
> > > 1+2+6 (=9) divides 126 --> HIT
> > > etc.
> > >
> > > Best,
> > > É.
> > >
> > >
> > >
> >
> > It takes Mathematica a couple of minutes to get
> >     {1, 2, 6, 250488, 279786, 1060566, 1414088,
> > 1767610, 2447460},
> > which is not in the OEIS.
> >
> > Regards,
> > John
> >
> >
> >
> >
> > _______________________________________________
> >
> > Seqfan Mailing list - http://list.seqfan.eu/
> >
>
>
>
>
>
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>
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>

```