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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,695

That expression gets the second square before the first. We could iterate again and get the third, fourth or fifth.

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I just coded it and it worked!

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,695

Hi Agnishom;

Which did you code?

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This: http://www.alpertron.com.ar/4SQUARES.HTM

Wait, something's wrong: it can't decompose numbers like 130, 520, 2080, 8320, 33280, 133120 and I can't understand why.

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'You have made another human being happy. There is no greater accomplishment.' -bobbym

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,695

All those numbers are divisible by 130. Can it do 16?

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Yes.

(All numbers between them and less than them can be done)

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'You have made another human being happy. There is no greater accomplishment.' -bobbym

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,695

There are

for 130. Maybe his algorithm is not correct.

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What they simply say:

*Last edited by Agnishom (2013-04-21 00:54:03)*

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'You have made another human being happy. There is no greater accomplishment.' -bobbym

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,695

Did you try his applet at the bottom and see if it works on 130?

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Let me do that now.

BTW Can you see this:

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'You have made another human being happy. There is no greater accomplishment.' -bobbym

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,695

Hi;

No, I can not.

**In mathematics, you don't understand things. You just get used to them.**

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Oh! Then #84 won't make sense to you.

Yes, it can decompose 130 and that is sad

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'You have made another human being happy. There is no greater accomplishment.' -bobbym

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,695

How did you express 130 in the form of 4^r * s?

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Repeated division by 4.

The problem is here I guess:

Subtract a square and check whether the result has the form 2^m (4k+1) where m is a non-negative integer.

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'You have made another human being happy. There is no greater accomplishment.' -bobbym

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,695

Hi;

There is no form 4^r *s = 130

Also, 130 is representable as the sum of 2 squares.

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(4^0)*(130) = 130

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'You have made another human being happy. There is no greater accomplishment.' -bobbym

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,695

What did you now get for this step?

2^m (4k+1)

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That is the problem, I can't do it. 4k + 1 isn't being a prime

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'You have made another human being happy. There is no greater accomplishment.' -bobbym

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,695

When you ran his applet, what was his answer for 130?

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7**2 + 9**2

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'You have made another human being happy. There is no greater accomplishment.' -bobbym

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,695

Maybe I am missing something but how do you know what square to subtract?

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I am starting from 0, then 1 then 4 then 9 then 16 and so on..

*Last edited by Agnishom (2013-04-21 05:15:28)*

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'You have made another human being happy. There is no greater accomplishment.' -bobbym

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,695

Let me look at it for awhile.

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look for what?

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'You have made another human being happy. There is no greater accomplishment.' -bobbym

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See this one: http://agnishom.tumblr.com/post/48531450618/splitting-an-integer-into-four-squares

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'You have made another human being happy. There is no greater accomplishment.' -bobbym

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