Mathematics – Combinatorics
Scientific paper
2000-11-12
Mathematics
Combinatorics
13 pages, 1 table, 1 figure
Scientific paper
Let $E_n^r=\{[\tau]_a=(\tau_1^{(a_1)},...,\tau_n^{(a_n)})| \tau\in S_n,\ 1\leq a_i\leq r\}$ be the set of all signed permutations on the symbols 1,2,...,n with signs 1,2,...,r. We prove, for every 2-letter signed pattern $[\tau]_a$, that the number of $[\tau]_a$-avoiding signed permutations in $E_n^r$ is given by the formula $\sum\limits_{j=0}^n j!(r-1)^j{n\choose j}^2$. Also we prove that there are only one Wilf class for r=1, four Wilf classes for r=2, and six Wilf classes for $r\geq 3$.
No associations
LandOfFree
Restricted single or double signed patterns does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Restricted single or double signed patterns, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Restricted single or double signed patterns will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-351117