I am currently reading the Algorithm Design Manual, but my mathematical notation has become a little rusty.
What does
mean?
+4
A:
Combination is the first thing that comes to mind...but without context, there are probably other meanings for the same notation.
Thomas Owens
2009-07-27 19:34:48
Binomial coefficient is the second one I was going to suggest, but I couldn't remember what it was. I think it's time for me to brush up on my discrete math.
Thomas Owens
2009-07-27 19:37:47
Not to be confused with the Legendre Symbol http://en.wikipedia.org/wiki/Legendre_symbol
Adam Rosenfield
2009-07-27 19:39:08
+10
A:
It means "n choose k", or in this case, "a choose b". It is a shorthand for the formula a!/(b!((a-b)!)).
Sorry for the many parenthesis, just didn't want amibuity. ! means factorial, 5! = 5*4*3*2*1, etc.
It is used for binomial expansion, and Pascal's Triangle.
Agor
2009-07-27 19:36:01