Köchel catalogue Horn Concerto No. 1, K. (412+514)/386b. In the decades after Mozart's death there were several attempts to catalogue his compositions, for example by Franz Gleißner and Johann Anton André (published in 1833), but it was not until 1862 that Ludwig von Köchel succeeded in producing a comprehensive listing. Köchel's 551-page catalogue was titled "Chronologisch-thematisches Verzeichnis sämmtlicher Tonwerke W. A. Mozarts" ("Chronological-thematic Catalogue of the Complete Musical Works of W. A. Mozart"). Köchel attempted to arrange the works in chronological order, but many compositions written before 1784 could only be estimated, although Leopold Mozart had compiled a partial list of his
Rencontres numbers Rencontres numbers In combinatorial mathematics, the rencontres numbers are a triangular array of integers that enumerate permutations of the set { 1, ..., "n" } with specified numbers of fixed points: in other words, partial derangements. ("Rencontre" is French for "encounter". By some accounts, the problem is named after a solitaire game.) For "n" ≥ 0 and 0 ≤ "k" ≤ "n", the rencontres number "D" is the number of permutations of { 1, ..., "n" } that have exactly "k" fixed points. For example, if seven presents are given to seven different people, but only two are destined to