[seqfan] Re: Sum divides concatenation
zak seidov
zakseidov at yahoo.com
Tue Sep 29 21:59:19 CEST 2009
with the earlist possible zero we have:
1, 0, 2, 6, 8, 10, 162, 420, 174, 486, 974, 4486, 1794, 20834, 26986, 16098, 19220, 19738, 58362, 60918, 48564, ...
--- On Tue, 9/29/09, Jack Brennen <jfb at brennen.net> wrote:
> From: Jack Brennen <jfb at brennen.net>
> Subject: [seqfan] Re: Sum divides concatenation
> To: "Sequence Fanatics Discussion list" <seqfan at list.seqfan.eu>
> Date: Tuesday, September 29, 2009, 3:02 PM
> If zero were allowed, wouldn't it
> have come earlier in the sequence?
>
> And John Layman's sequence (quoted below) appears to assume
> that the
> sequence is strictly increasing, something which wasn't a
> condition
> of the sequence as originally specified.
>
>
>
> zak seidov wrote:
> > 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
> >>>
> >>>
> >>>
> >>>
> >>>
> _______________________________________________
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> >>>
> >>
> >>
> >>
> >>
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> >
> >
> >
> >
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