Results 41 to 50 of about 365 (70)

Sorting inversion sequences [PDF]

Discrete Mathematics & Theoretical Computer Science
We consider the avoidance of patterns in inversion sequences that relate sorting via sorting machines including data structures such as pop stacks and stacks.
Toufik Mansour, Howard Skogman, Rebecca Smith   +2 more
doaj   +1 more source

Cyclic to Random Transposition Shuffles [PDF]

, 2012
Consider a permutation $\sigma\in S_n$ as a deck of cards numbered from 1 to $n$ and laid out in a row, where $\sigma_j$ denotes the number of the card that is in the $j$-th position from the left.\rm\ We define two cyclic to random transposition ...
Pinsky, Ross G.
core  

Restricted ascent sequences and Catalan numbers

, 2014
Ascent sequences are those consisting of non-negative integers in which the size of each letter is restricted by the number of ascents preceding it and have been shown to be equinumerous with the (2+2)-free posets of the same size.
Callan, David, Mansour, Toufik, Shattuck, Mark   +2 more
core   +1 more source

On the problem of Molluzzo for the modulus 4

, 2012
We solve the currently smallest open case in the 1976 problem of Molluzzo on $\mathbb{Z}/m\mathbb{Z}$, namely the case $m=4$. This amounts to constructing, for all positive integer $n$ congruent to $0$ or $7 \bmod{8}$, a sequence of integers modulo $4 ...
Chappelon, Jonathan, Eliahou, Shalom
core   +3 more sources

Bounded Littlewood identity related to alternating sign matrices

Forum of Mathematics, Sigma
An identity that is reminiscent of the Littlewood identity plays a fundamental role in recent proofs of the facts that alternating sign triangles are equinumerous with totally symmetric self-complementary plane partitions and that alternating sign ...
Ilse Fischer
doaj   +1 more source

and [PDF]

. We study the descent distribution over the set of centrosymmetric permutations that avoid a pattern of length 3. In the most puzzling case, namely, τ = 123 and n even, our main tool is a bijection that associates a Dyck pre x of length 2n to every ...
Flavio Bonetti, Marilena Barnabei, Matteo Silimbani   +2 more
core  

Identities on the k-ary Lyndon words related to a family of zeta functions

, 2016
The main aim of this paper is to investigate and introduce relations between the numbers of k-ary Lyndon words and unified zeta-type functions which was defined by Ozden et al [15, p. 2785].
Kucukoglu, Irem, Simsek, Yilmaz
core  

The Eulerian numbers on restricted centrosymmetric permutations

, 2009
We study the descent distribution over the set of centrosymmetric permutations that avoid the pattern of length 3. Our main tool in the most puzzling case, namely, $\tau=123$ and $n$ even, is a bijection that associates a Dyck prefix of length $2n$ to ...
Barnabei, Marilena, Bonetti, Flavio, Silimbani, Matteo   +2 more
core  

Counting occurrences of 132 in an even permutation

, 2002
We study the generating function for the number of even (or odd) permutations on n letters containing exactly $r\gs0$ occurrences of 132. It is shown that finding this function for a given r amounts to a routine check of all permutations in $S_{2r ...
Mansour, T.
core   +1 more source

Grid classes and the Fibonacci dichotomy for restricted permutations

, 2006
We introduce and characterise grid classes, which are natural generalisations of other well-studied permutation classes. This characterisation allows us to give a new, short proof of the Fibonacci dichotomy: the number of permutations of length n in a ...
Huczynska, Sophie, Vatter, Vincent
core