Compositions colored by simplicial polytopic numbers
| Autor: | Daniel Birmajer, Michael D. Weiner, Juan B. Gil |
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| Rok vydání: | 2018 |
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| Zdroj: | Journal of Combinatorics. 9:221-232 |
| ISSN: | 2150-959X 2156-3527 |
| DOI: | 10.4310/joc.2018.v9.n2.a1 |
| Popis: | For a given integer $d\ge 1$, we consider $\binom{n+d-1}{d}$-color compositions of a positive integer $\nu$ for which each part of size $n$ admits $\binom{n+d-1}{d}$ colors. We give explicit formulas for the enumeration of such compositions, generalizing existing results for $n$-color compositions (case $d=1$) and $\binom{n+1}{2}$-color compositions (case $d=2$). In addition, we give bijections from the set of $\binom{n+d-1}{d}$-color compositions of $\nu$ to the set of compositions of $(d+1)\nu - 1$ having only parts of size $1$ and $d+1$, the set of compositions of $(d+1)\nu$ having only parts of size congruent to $1$ modulo $d+1$, and the set of compositions of $(d+1)\nu + d$ having no parts of size less than $d+1$. Our results rely on basic properties of partial Bell polynomials and on a suitable adaptation of known bijections for $n$-color compositions. Comment: 9 pages. Improved version accepted for publication |
| Databáze: | OpenAIRE |
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