{ "id": "2310.08615", "version": "v1", "published": "2023-10-12T12:34:05.000Z", "updated": "2023-10-12T12:34:05.000Z", "title": "Alternative combinatorial sum for the probability mass function of the Poisson distribution of order $k$", "authors": [ "S. R. Mane" ], "comment": "6 pages", "categories": [ "math.PR", "math.CO" ], "abstract": "Kostadinova and Minkova published an expression for the probability mass function (pmf) of the Poisson distribution of order $k$, as a combinatorial sum ($\\mathit{Pliska~Stud.~Math.~Bulgar.}\\ {\\bf 22},\\ 117-128\\ (2013)$). Inspired by their elegant solution, this note presents an alternative combinatorial sum for the pmf of the Poisson distribution of order $k$. The terms are partitioned into blocks of length $k$ (as opposed to $k+1$ by Kostadinova and Minkova). The new sum offers an advantage in the following sense. For $n\\in[rk+1,(r+1)k]$, the lowest power of $\\lambda$ in the pmf is $\\lambda^{r+1}$. Hence the lower limit of summation can be increased, to avoid needlessly calculating terms which cancel to identically zero.", "revisions": [ { "version": "v1", "updated": "2023-10-12T12:34:05.000Z" } ], "analyses": { "subjects": [ "60E05", "39B05", "11B37", "05-08" ], "keywords": [ "probability mass function", "alternative combinatorial sum", "poisson distribution", "elegant solution", "kostadinova" ], "note": { "typesetting": "TeX", "pages": 6, "language": "en", "license": "arXiv", "status": "editable" } } }