Find a closed-form expression for F(a,b) where:

F(a,b) = F(a-1,b) + F(a-1,b-1),

F(a,0) = 1 for all a

F(0,b) = 0 for all b

a and b are positive integers

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# Recursion

Started by mmiguel, Oct 21 2012 10:43 AM

2 replies to this topic

### #1

Posted 21 October 2012 - 10:43 AM

### #2

Posted 21 October 2012 - 02:55 PM

What does F(0,0) evaluate to? you need it for F(1,1)

Spoiler for

**Edited by Anza Power, 21 October 2012 - 03:04 PM.**

### #3

Posted 21 October 2012 - 07:53 PM

What does F(0,0) evaluate to? you need it for F(1,1)

Spoiler for

F(0,0) = 1

Sorry for leaving that out.

Nice work, you are correct!

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