Speaker: |
Dominique Foata, Strasbourg |

Title: |
Entringer numbers and Poupard Calculus |

Date: |
13.11. 2013 14:00--15:30 |

Location: |
RISC Seminar room pond |

Abstract: |
Refinements of the celebrated tangent and secant numbers give rise to bivariate statistical distributions that can be expressed, either by a finite difference equation system, or by a three-variate exponential generating function. The underlying combinatorial sets, counted by tangent and secant numbers, are the alternating permutations, or the AndrĂ© permutations of the two kinds, or still the binary increasing trees. Emphasis will be made on the calculation of the involved series. |

VCAL file: |