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Topic: No Putnam spoilers please
Replies: 15   Last Post: Dec 14, 2012 6:05 AM

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Dr J R Stockton

Posts: 3
Registered: 12/13/12
Re: No Putnam spoilers please
Posted: Dec 13, 2012 2:01 PM
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In sci.math message <MPG.2b2efda4be25e802989692@news.eternal-
september.org>, Sun, 9 Dec 2012 19:58:25, Wasell
<Wasell@example.invalid> posted:

>On Sat, 8 Dec 2012 19:13:02 +0000, in article
><1tj7wWW+E5wQFwvR@invalid.uk.co.demon.merlyn.invalid>, Dr J R Stockton
>wrote:
>

>> Can anyone (or more) please provide here the last ten decimal digits
>(in
>> order) of ((3^349)-1)/2, freshly and independently calculated and not
>> copied from any other medium, and not using my LongCalc or VastCalc?

>
>$ perl -Mbigint -e 'print substr( ((3**349)-1)/2, -10 )'
>7379284041



Real Life intervened. Thanks to all four. I've not checked the whole
of their long numbers, but parts are right so no doubt about the rest.
I had also used Richard's approach, in JavaScript.


Some years ago, while reading a book that showed (roughly)

(3^349-1)/2
=
three lines of digits
=
two lines of digits
*
two lines of digits

I noticed a missing digit near the beginning of the second "two lines",
and reported it. I was evidently checking the expression against the
multiplication. I have now noticed that your second 7 is, in the book,
an 8 - 7389284041 - and wanted a cross-check before reporting the new
fault. OTOH, before doing that, I should re-check ALL digits.

Mathematicians, or some of them, might recognise the expression.

See books.google.co.uk/books?isbn=0195130820, page 107.

7389284041 seems to be a Harshad number as well as one used by Indians.

Again thanks.

--
(c) John Stockton, nr London, UK. Mail via homepage. Turnpike v6.05 MIME.
Web <http://www.merlyn.demon.co.uk/> - FAQqish topics, acronyms and links;
Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.



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