Arnold Knopfmacher ; Toufik Mansour
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Record statistics in integer compositions
dmtcs:2691 -
Discrete Mathematics & Theoretical Computer Science,
January 1, 2009,
DMTCS Proceedings vol. AK, 21st International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC 2009)
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https://doi.org/10.46298/dmtcs.2691
Record statistics in integer compositionsArticle
Authors: Arnold Knopfmacher 1; Toufik Mansour 2
0000-0003-1962-043X##0000-0001-8028-2391
Arnold Knopfmacher;Toufik Mansour
1 The John Knopfmacher Centre for Applicable Analysis and Number Theory [Johannesburg]
2 Department of Mathematics [Haïfa]
A $\textit{composition}$ $\sigma =a_1 a_2 \ldots a_m$ of $n$ is an ordered collection of positive integers whose sum is $n$. An element $a_i$ in $\sigma$ is a strong (weak) $\textit{record}$ if $a_i> a_j (a_i \geq a_j)$ for all $j=1,2,\ldots,i-1$. Furthermore, the position of this record is $i$. We derive generating functions for the total number of strong (weak) records in all compositions of $n$, as well as for the sum of the positions of the records in all compositions of $n$, where the parts $a_i$ belong to a fixed subset $A$ of the natural numbers. In particular when $A=\mathbb{N}$, we find the asymptotic mean values for the number, and for the sum of positions, of records in compositions of $n$.