A combinatorial survey of identities for the double factorial
Abstract
We survey combinatorial interpretations of some dozen identities for the double factorial such as, for instance, (2n-2)!! + Sum_{k=2}^{n} (2n-1)!!(2k-4)!!/(2k-1)!! = (2n-1)!!. Our methods are mostly bijective.
- Publication:
-
arXiv e-prints
- Pub Date:
- June 2009
- DOI:
- 10.48550/arXiv.0906.1317
- arXiv:
- arXiv:0906.1317
- Bibcode:
- 2009arXiv0906.1317C
- Keywords:
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- Mathematics - Combinatorics;
- 05A15
- E-Print:
- 29 pages