Articles
David Callan
2023
 (with Toufik Mansour)
Three classes of inversion sequences counted by large Schroder numbers, Aust J. Combin.,
submitted.
 (with Toufik Mansour)
Inversion sequences avoiding a quadruple of length3 patterns,
INTEGERS, to appear.
 (with Tewodros Amdeberhan)
Gaussian Inequality, Rocky Mountain Journal of Mathematics, to appear.
 (with Vit Jelinek and Toufik Mansour)
Inversion Sequences Avoiding a Triple of Patterns of 3 Letters, The Electronic Journal of Combinatorics,
30(3), Article P3.19, Published 20230811 (39pp).

The number of {1243,2134}avoiding permutations,
Discrete Mathematics & Theoretical Computer Science, 22 no. 2, Permutation Patterns 2019, published on March 03, 2023.
 (with Toufik Mansour)
Restricted inversion sequences and Schroder paths,
Quaestiones Mathematicae, Published online: 03 Feb 2023.
2022
2021
2019
2018
 (with Toufik Mansour)
Enumeration of small Wilf classes avoiding 1324 and two other 4letter patterns,
Pure Math. Appl. (PU.M.A.), 27 Issue 1, 2018, 32–61.
 (with Toufik Mansour)
Enumeration of small Wilf classes avoiding 1342 and two other 4letter patterns,
Pure Math. Appl. (PU.M.A.), 27 Issue 1, 2018, 62–97.
 (with Toufik Mansour)
Five Subsets of Permutations Enumerated as Weak
Sorting Permutations,
Southeast Asian Bull. Math., 42 Issue 3, 2018, 327–340.
2017
 (with Toufik Mansour and Mark Shattuck)
Twelve subsets of permutations enumerated as maximally clustered permutations,
Ann. Math. Inform., 47, 2017, 41–74.
 (with Toufik Mansour)
On permutations avoiding 1324, 2143, and another 4letter pattern,
Pure Math. Appl. (PU.M.A.), 26 Issue 1, 2017, 1–10.
 (with Toufik Mansour)
On permutations avoiding 1243, 2134, and another 4letter pattern,
Pure Math. Appl. (PU.M.A.), 26 Issue 1, 2017, 11–21.
 (with Toufik Mansour and Mark Shattuck)
Wilf classification of triples of 4letter patterns I,
Discrete Math. Theor. Comput. Sci., 19, Issue 1, Paper No. 5, 2017, 35pp.
 (with Toufik Mansour and Mark Shattuck)
Wilf classification of triples of 4letter patterns II,
Discrete Math. Theor. Comput. Sci., 19, Issue 1, Paper No. 6, 2017, 44pp.
 (with Tewodros Amdeberhan, Hideyuki Ohtsuka, and Roberto Tauraso)
Revitalized automatic proofs: demonstrations,
INTEGERS, 17, Paper No. A16, 2017, 12pp.
2016
2015
2014
2013
2012
2011
2010
2009
2008

Card deals, lattice paths, abelian words and combinatorial identities,
(10pp).

Klazar trees and perfect matchings,
European J.
Combinatorics 31 (2010), 1265–1282.
 (with Evangelos Georgiadis and QingHu Hou)
Circular digraph walks, kbalanced strings, lattice paths and Chebychev polynomials,
The Electronic Journal of Combinatorics,
15(1), Article R108, 2008 (12pp).

Pattern avoidance in "flattened" partitions,
Discrete
Mathematics, 309, Issue 12, 2009, 4187–4191.
2007

A combinatorial interpretation for the identity
,
Journal
of Integer Sequences,
11, Article 08.3.4, 2008.

Sets, lists and noncrossing partitions,
Journal
of Integer Sequences,
11, Article 08.1.3, 2008.

Bijections from Dyck paths to 321avoiding permutations revisited.

A determinant of Stirling cycle numbers
counts unlabeled acyclic singlesource automata,
Discrete Mathematics & Theoretical Computer Science,
10, Issue 2, 2008.
2006
2005
2004
2003

A uniformly distributed parameter on a class of lattice paths,
The Electronic Journal of Combinatorics,
11(1), Article R82, 2004 (8pp).

A combinatorial derivation of the number of labeled forests,
Journal
of Integer Sequences,
6, Article 03.4.7, 2003.

Counting stabilizedintervalfree permutations,
Journal
of Integer Sequences,
7, Article 04.1.8, 2004.
 (with Helmut Prodinger)
An involutory matrix of eigenvectors,
Fibonacci Quarterly 41 (May 2003), 105–107.
2002
2000
1999
1997
1995
1991
1985
1978
1976