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From: James Waldby on 20 Apr 2010 14:07
On Tue, 20 Apr 2010 09:54:47 -0700, Mensanator wrote:
> On Apr 20, 9:41 am, mukesh tiwari [..] wrote:

[re <http://projecteuler.net/index.php?section=problems&id=140>]

>> Hello everyone, I am trying to solve this problem but i am not getting
>> efficient solution. Here is my analysis.
>>
>> A=(x^2+3x)/(1-x-x^2)
>> x=-(A+1)+Sqrt(5A^2+14A+1)/2(A+3) since x is rational so 5A^2+14A+1 must
>> be a perfect square.
>> 5A^2+14A+1=D^2
>> A=-14+Sqrt(20D^2+176)/10.. This is the value of A which we have to add
>> upto 30 numbers. Now i am iteration D from 1 to infinity and got some
>> values but it tool almost 30 mins and produce only 21 values.
>
> What are you using? An abacus?

I don't think you can iterate to infinity in only 30 minutes
using an abacus. In fact, Mukesh must have used a really
really fast computer to get there at all.

>> 2
>> 5
>> 21
>> 42
>> 152
[snip 15 lines]
>> 747173957
>> kindly give me some more insights.
>> Thank you

--
jiw
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