2 search results - page 1 / 1 » Riordan paths and derangements |
DM
2008
13 years 5 months ago
2008
Riordan paths are Motzkin paths without horizontal steps on the x-axis. We establish a correspondence between Riordan paths and (321, 3
EJC
2010
13 years 5 months ago
2010
A classical result of Euler states that the tangent numbers are an alternating sum of Eulerian numbers. A dual result of Roselle states that the secant numbers can be obtained by a...