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   Pascal’s Triangle
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   Author  Topic: Pascal’s Triangle  (Read 702 times)
Benny
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Pascal’s Triangle  
« on: Sep 25th, 2009, 2:36pm »
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Is there a way to determine how many odd elements there are in a particular row?
 
If we know how many there are in the n-th row can we predict for the (n+1)-th row?
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towr
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Re: Pascal’s Triangle  
« Reply #1 on: Sep 25th, 2009, 3:04pm »
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Try drawing pascal's triangle modulo 2 and see if you notice anything. After a 16 or 32 rows or so it should be apparent. If you don't see anything by that time, draw lines through the 1s.
« Last Edit: Sep 25th, 2009, 3:10pm by towr » IP Logged

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Grimbal
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Re: Pascal’s Triangle  
« Reply #2 on: Sep 28th, 2009, 1:06am »
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Or just compute the sequence and see if you notice a pattern:
1 2 2 4 2 4 4 8 2 4 4 8 4 8 8 16 2 4 4 8 ...
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Benny
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Re: Pascal’s Triangle  
« Reply #3 on: Sep 28th, 2009, 9:16am »
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on Sep 28th, 2009, 1:06am, Grimbal wrote:
Or just compute the sequence and see if you notice a pattern:
1 2 2 4 2 4 4 8 2 4 4 8 4 8 8 16 2 4 4 8 ...

 
I've just found a discussion of the problem here
 
Quote:

An interesting problem is to determine the number of odd coefficients in the expansion of (x+y)n. Essentially, this reduces to determining the number of odd values in the n-th row of Pascal's Triangle.

 
 
 
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Re: Pascal’s Triangle  
« Reply #4 on: Sep 28th, 2009, 10:00am »
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http://www.research.att.com/~njas/sequences/A001316
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