History of Science and Engineering Annotation << Back Investigations of Lydwig Ottinger in Combinatorial Theory of Enumeration Malykh A.E. Yankovich E.I. The scientific contribution of L. Oettinger in the development of combinatorial theory of enumeration include: designation of the combinatorial types of compositions with limited and unlimited repeats, permutations and combinations, containing a complexes of composition of different classes; combinations and arrangements with certain sum, as well as other types of compositions. He developed the procedure of counting of different combinatorial complexes. The scientist continued research, associated with binomial and polynomial theorems. Oettinger showed the practical importance of obtained results. A scientist decided combinatorial problems who formulated by J.I Bernoulli in this « Ars conjectandi». He has written the book, which became one of the best on the enumerating combinatorial theory of XIXth century. Keywords: combinatorial analysis; permutations and compositions with restricted and unrestricted repeating of elements; combinations and permutations with given sum; combinatorial complexis; binomial and polynomial theorems. Contacts: E-mail: malych@pspu.ru Pp. 05-16.