A007666

[Max Alekseyev]

At http://euler.free.fr/resta.htm it is said that only the following
ranges (displayed in italic there) are finished:

0 .. 200000
200000 .. 272580
300000 .. 350000
350000 .. 375012
400000 .. 404147
450000 .. 468864
500000 .. 502464

Is that really true that "they've checked all numbers up to 700,000" ?
If so, where I can find details?

Max

On 6/10/07, Jon Schoenfield <jonscho at hiwaay.net> wrote:
>
>
> Thanks!
>
> So would a comment at A007666 that "a(6) has no solution less than 700000"
> be appropriate?
>
> Or maybe "a(6) is either 0 (no solution) or greater than 700000"?  Or would
> some other wording be better?
>
> Thanks again,
>
> -- Jon
>
> ----- Original Message -----
> From: Robert Gerbicz
> To: Sequence Fans
> Sent: Sunday, June 10, 2007 3:00 AM
> Subject: [Norton AntiSpam]
>
> See http://euler.free.fr/
> As you can see on their Resta page they've checked all numbers up to
> 700,000. ( using many modular tricks to speed up the search.)
> This is a really hard problem, both in running time and memory. But there
> are known solutions for n=7 and n=8, I don't know if these are the smallest
> or not:
> 568^7=525^7+439^7+430^7+413^7+266^7+258^7+127^7  found by
> Mark Dodrill in 03/20/1999
>
> 1409^8=1324^8+1190^8+1088^8+748^8+524^8+478^8+223^8+90^8
> found by Scott I. Chase about in 2000.