There are EXACTLY 1493804444499093354916284290188948031229880469556 ways to derange a standard deck of cards (ignoring suits) [and many other such useful facts]
Shalosh B. Ekhad,
Christoph Koutschan,
Doron Zeilberger
Affiliations
Shalosh B. Ekhad
Rutgers University (New Brunswick)
Christoph Koutschan
Johann Radon Institute for Computational and Applied Mathematics (RICAM)
