Possible Incorrect Summation
- To: mathgroup at smc.vnet.net
- Subject: [mg31034] Possible Incorrect Summation
- From: Richard Palmer <mapsinc at bellatlantic.net>
- Date: Fri, 5 Oct 2001 01:22:45 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
I believe
Sum[ (-1)^k Binomial[2 n, k] Binomial[2k, k] Binomial[4n - 2k, 2n -
k],{k,0,2n}]
is a special case of Dixon's Identity and should equal Binomial[2n,n]^2.
Previously the SymbolicSum package returned a value which could be
simplified to the result. The latest version of Mathematica returns a value
which is is not this result as can be seen by graphing the difference. What
has changed?