Köchel catalogue son's earlier works; Mozart's catalogue of his own compositions (begun in February 1784 with K. 449) allows relatively precise dating of many of his later works. The catalogue included the opening bars of each piece, known as an incipit. Köchel divided the corpus into a main chronology of 626 works, and five appendices ("" in German, abbreviated to "Anh.") The appendices (Anh. I-V) included: Since Köchel published his original catalogue in 1863 (now referred to as K), the dating of Mozart's compositions has been subject to constant revision. Many more pieces have since been found, re-dated, re-attributed and re-numbered, requiring
Stirling numbers of the second kind for Stirling numbers of the second kind. The brace notation formula_2 was used by Imanuel Marx and Antonio Salmeri in 1962 for variants of these numbers. This led Knuth to use it, as shown here, in the first volume of "The Art of Computer Programming" (1968). However, according to the third edition of "The Art of Computer Programming", this notation was also used earlier by Jovan Karamata in 1935. The notation "S"("n", "k") was used by Richard Stanley in his book "Enumerative Combinatorics". Since the Stirling number formula_15 counts set partitions of an "n"-element set into "k" parts, the sum