[seqfan] Re: Sum divides concatenation

[Charles Greathouse]

It's not in the database.  The terms are
1, 2, 6, 250488, 19986, 118030, 133970, 693810, 2231328, 3407286,
5733260, 25176334, 75529002, ...

The next term is more than 100 million.  A good program could find
these values quickly, but I just used a few minutes of brute force.

Charles Greathouse
Analyst/Programmer
Case Western Reserve University

On Mon, Sep 28, 2009 at 12:35 PM, Jack Brennen <jfb at brennen.net> wrote:
> The next term would be 250488, if that's any help:
>
>   126250488 == (1+2+6+250488) * 504
>
> 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.
>>
>>
>> _______________________________________________
>>
>> Seqfan Mailing list - http://list.seqfan.eu/
>>
>>
>
>
>
> _______________________________________________
>
> Seqfan Mailing list - http://list.seqfan.eu/
>