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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,532

Where does what come from?

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,776

Hmmmm, the recurrence of course.

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,532

I found it using some simple casework.

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,776

Casework is never simple and you must always be thinking of the form of your solution. Most math types are notorioulsy bad problem solvers. Just take a look at all those equations that they think are beautiful and are not worth a dime computationally.

What if this solution takes 1.2 million years to run?

*Last edited by bobbym (2013-02-20 08:15:40)*

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,532

I hope it doesn't. I don't have much time. We have some tests next week.

I proposed that recurrence as a pathway to an analytic solution, not for computation.

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,776

I proposed that recurrence as a pathway to an analytic solution, not for computation

It is not going to be easy to solve that recurrence.

*Last edited by bobbym (2013-02-20 10:21:28)*

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,532

I think a multivariate GF can be found for A(n,k) from the recurrence.

Here lies the reader who will never open this book. He is forever dead.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,776

You will have to do it by hand but why would you? Why do all that work when you do not even know whether it works or not.

I stress my approach of first having the answer. The experimental way. I have not convinced you of this yet and the remnants of your math education you are tenaciously holding on to.

*Last edited by bobbym (2013-02-21 03:48:55)*

Of course that result can be rigorously obtained, but who cares?

Combinatorics is Algebra and Algebra is Combinatorics.

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