Mathematics – Combinatorics
Scientific paper
2012-03-24
Mathematics
Combinatorics
7 pages
Scientific paper
We give a direct combinatorial proof of a famous identity, $$ \sum_{i+j=n} m{2i}{i} \binom{2j}{j} = 4^n $$ by actually counting pairs of $k$-subsets of $2k$-sets. Then we discuss two different generalizations of the identity, and end the paper by presenting in explicit form the ordinary generating function of the sequence $(\strut\binom{2n+k}{n})_{n\in\mathds{N}_0}$, where $k\in\mathds{R}$.
de Oliveira António Guedes
Duarte Rui
No associations
LandOfFree
New developments of an old identity does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with New developments of an old identity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and New developments of an old identity will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-39171