** An empirical method for solving (rigorously!) algebraic functional equations of the form F(P(x,t), P(x,1),x,t)=0** (with Doron Zeilberger),
arXiv:1412.8360, 2014.

**Counting unlabeled k-trees ** (with Andrew Gainer-Dewar),

pdf file.

**Enumeration of bipartite graphs and bipartite blocks ** (with Andrew Gainer-Dewar), *Electronic J. Combin*. 21 (2) (2014), Paper #P2.40.

Link to E-JC.

**A simple proof of Andrews's _{5}F_{4} evaluation, ** Ramanujan Journal, 2013.

pdf file.

**Compositions and Fibonacci identities ** (with Ji Li), * J. Integer Sequences, * Article 13.4.5, 2013.

Link to JIS,

**Jacobi-Stirling polynomials and P-partitions** (with Zhicong Lin and Jiang Zeng), *European J. Combin.* 33 (2012), 1987–2000.

pdf file.

**A bijection between words and multisets of necklaces** (with A. Restivo and C. Reutenauer), *European J. Combin.* 33 (2012), 1537–1546.

pdf file.

**Enumeration of point-determining graphs ** (with Ji Li),
J. Combinatorial Theory Ser. A 118 (2011), 591–612.

pdf file.

** The limit as p → ∞ of the Hilbert-Kunz multiplicity of sum(x_i^(d_i))i ** (with Paul Monsky),
arXiv:1007.2004, 2010.

** A note on 2-distant noncrossing partitions and weighted Motzkin paths** (with Jang Soo Kim), *Discrete Math.*, 310 (2010), 3421–3425.

pdf file.

**Symmetrically constrained compositions** (with Matthias Beck, Sunyoung Lee, and Carla D. Savage), *Ramanujan Journal* 23 (2010), 355–369.

pdf file.

**Note on enumeration of partitions contained in a given shape ** (with Nicholas Loehr), *Linear Algebra Appl.* 432 (2010), 583–585.

pdf file.

**Multilinear generating functions for Charlier
polynomials** (with Pallavi Jayawant), *J. Statist. Inf. Plann.*
140 (2010), 2230–2236.

pdf file.

**The sum : a third proof of its closed form** (with Peter J. Larcombe), *Util. Math.* 80 (2009), 59–63.

pdf file.

**A major statistic for matchings and partitions** (with
William Y. C. Chen, Arthur L.B. Yang, and
Catherine H. Yan), *J. Combin. Theory Ser. A*, 115 (2008), 1069–1076.

pdf file.

**A unified elementary approach to the Dyson, Morris, Aomoto, and Forrester constant term identities** (with Lun Lv, Guoce Xin, and Yue Zhou), *J. Combin. Theory Ser. A*, 115 (2008), 1417–1435.

pdf file.

**The joint distribution of descent and major index over
restricted sets of permutations ** (with Sylvie D. Corteel, Carla Savage, and Herbert S. Wilf),
*Annals of Combinatorics* 11 (2007), 375–386.

pdf file

**Three proofs and a generalization of the Goulden-Litsyn-Shevelev conjecture on a sequence arising in algebraic geometry **(with Brian Drake and Guoce Xin), * J. Integer Seq. * 10 (2007), Article 07.3.7.

Link to JIS

**On the descent numbers and major indices for the hyperoctahedral group ** (with Chak-On Chow), *Adv. in Appl. Math.* 38 (2007), 275–301.

pdf file

**A refinement of Cayley's formula for trees ** (with Seunghyun Seo),
*Electronic J. Combinatorics* 11, no. 2 (2004–2006), R27.

Link to E-JC

** A short proof of the Zeilberger-Bressoud q-Dyson theorem** (with Guoce Xin),
*Proc. Amer. Math. Soc.* 134 (2006), 2179–2187.

pdf file

** The generating function of ternary trees and continued fractions**
(with Guoce Xin),* Electronic J. Combinatorics* 13, no. 1 (2006), R53.

Link to E-JC

** Symmetric inclusion-exclusion**, *Séminaire Lotharingien de Combinatorie* 54 (2005), B54b.

Link to SLC

** A combinatorial interpretation of the numbers 6(2n)! /n! (n+2)! ** (with Guoce Xin),
* J. Integer Seq.* 8 (2005), no. 2, Article 05.2.3,
13 pp.

Link to JIS

**A triple lacunary generating function for Hermite polynomials ** (with Pallavi Jayawant), *Electronic Journal of Combinatorics* 12 (2005), Research Paper 30, 14 pp.

Link to E-JC

** Hypergraphs and a functional equation of Bouwkamp and de Bruijn**
(with Louis H. Kalikow)
*J. Combinatorial Theory, Ser. A* 110 (2005), 275–289.

pdf file

**On Miki's identity for Bernoulli numbers,
**
* J. Number Theory,* 110 (2005), 75–82.

pdf file

**Signed Mahonians **(with Ron M. Adin and Yuval Roichman),
*J. Combin. Theory Ser. A* 109 (2005), 25–43.

pdf file

Slides from a talk on **Rational functions with nonnegative power series coefficients,*** 50th Seminaire Lotharingien de Combinatoire*, March 25, 2003.

pdf file

** Applications of the classical umbral
calculus**
*Algebra Universalis* 49 (2003), 397–434.

dvi file

pdf file

** The polynomial part of a restricted partition function
related to the Frobenius problem**
(with Matthias Beck and Takao Komatsu)
*Electronic J. Combinatorics*
8 (2001), No. 1, N7 (5 pages).

dvi file

pdf file

Link to E-JC

** The specification of 2-trees
**
(with Tom Fowler, Gilbert Labelle, and Pierre Leroux),
* Advances in Applied Math.* 28 (2002), 145–168.

pdf file

gzipped postscript file

**
Acyclic orientations and chromatic generating functions,
*** Discrete Math.* 232 (2001), 119–130.

dvi file

pdf file

gzipped postscript file

**
On the order of Stirling numbers and
alternating binomial coefficient sums
**
(with Tamas Lengyel), * Fibonacci Quarterly,*
39 (2001), 444–454.

pdf file

**
The Smith College diploma problem,
**
* Amer. Math. Monthly* 108 (2001), 55–57.

dvi file

pdf file

gzipped postscript file

**
On the number of convex polyominoes,
**
* Annales des Sciences Mathemathiques
du Quebec,* 24 (2000), 63–66.

dvi file

pdf file

gzipped postscript file

**
Tilings of diamonds and hexagons with defects
**
(with Harald Helfgott),*Electronic J. Combinatorics* 6, No. 1
(1999), R16 (21 pages).

gzipped postscript file

pdf file

**
Wolstenholme revisited
**
* Amer. Math. Monthly* 105 (1998), 657–658.

pdf file

**Lattice walks in Z ^{d} and permutations with no long
ascending subsequences** (with Jonathan Weinstein and Herbert S. Wilf),

Link to EJC

** Lattice paths and Faber polynomials** (with Sangwook Ree),
in
*Advances in Combinatorial Methods and Applications to
Probability and Statistics*, ed. N. Balakrishnan, Birkhauser Boston, 1997,
pp. 3–13.

dvi file

pdf file

AMSTeX file

**Cylindric partitions ** (with C. Krattenthaler), *Trans. Amer. Math.
Soc.* 349 (1997), 429–479.

Link to TAMS

**Generating functions and generalized Dedekind sums, **
*Electronic J. Combinatorics * 4, No. 2, Wilf Festschrift
(1997), R11 (17 pages).

Link to EJC

**Even and odd pairs of lattice paths with multiple intersections **
(with Walter Shur), *J. Combin. Theory Ser. A *75 (1996),
243–253.

gzipped postscript file

pdf file

**Counting pairs of lattice paths by intersections **
(with Wayne Goddard, Walter Shur, Herbert S. Wilf, and Lily Yen), *J. Combin. Theory Ser. A*
74 (1996), 173–187.

gzipped postscript file

**The Tutte polynomial of a graph, depth-first search, and simplicial complex partitions**
(with Bruce Sagan),* Electronic J. Combinatorics*
3, No. 2, Foata Festschrift (1996), R9 (36 pages).

Link to EJC

**Counting forests by descents and leaves,** *Electronic J. Combinatorics
3, * No. 2, Foata Festschrift (1996), R8 (5 pages).

Link to EJC

**Counting acyclic digraphs by sources and sinks, **
*Discrete Math.* 160 (1996), 253–258.

pdf file

AMSTeX file

** Enumerative applications of a decomposition for graphs and
digraphs, **
* Discrete Math.
* 139 (1995), 257–271.

pdf file

**Lagrange inversion for species, ** (with G. Labelle),
*J. Combin. Theory Ser. A* 72 (1995), 95–117.

pdf file

** Algebraic enumeration** (with R. P. Stanley), in
*Handbook of
Combinatorics* ed. R. L. Graham, M. Grotschel, and L. Lovasz,
Elsevier and MIT Press, 1995, pp. 1021–1062.

pdf file

** Finding identities with the WZ method.,**
* J. Symbolic
Comput. * 20 (1995), 537–566.

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** Counting paths in Young's lattice,**
* J. Statistical Planning and
Inference * 34 (1993), 125–134.

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**Super ballot numbers, **
* J. Symbolic Computation* 14 (1992),
179–194.

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**A coloring problem, **
* Amer. Math. Monthly* 98 (1991),
530–533.

pdf file

**Symmetric functions and P-recursiveness, **
* J. Combin. Theory Ser. A * 53
(1990), 257–285.

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** Generalized rook polynomials and orthogonal polynomials**, in
*q-Series and Partitions,* ed. D. Stanton, *The IMA Volumes in
Mathematics and Its Applications*, Vol. 18, Springer-Verlag, New York, 1989,
pp. 159–176.

pdf file

**Determinants, paths, and plane partitions **
(with X. G. Viennot), preprint, 1989

pdf file

dvi file

**Enumerative applications of symmetric functions, **
* Séminaire Lotharingien de Combinatoire * B17a (1987), 17 pp.

Link to SLC

** Counting three-line Latin rectangles**, in
*Combinatoire
énumerative,* ed. G. Labelle and P. Leroux, *Lecture Notes in
Mathematics*, Vol. 1234, Springer-Verlag, 1986, pp. 106–111.

pdf file

**A probabilistic method for lattice path enumeration, **
* J. Statist. Plann. Inference * 14
(1986), 49–58.

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** Combinatorial proofs of congruences,** in
* Enumeration and Design, * ed. David M. Jackson and Scott A. Vanstone, Academic Press, Toronto, 1984, pp. 157–197.

pdf file

** Multipartite P-partitions and inner products of skew Schur functions, **
* Contemp. Math. * 34
(1984), 289–301.

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** Some congruences for generalized Euler numbers**,
* Canad. J. Math. * 35 (1983), 687–709.

pdf file

**A factorization for formal Laurent series and lattice path enumeration **
* J. Combin. Theory Ser. A *28
(1980), 321–337.

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**Permutation statistics and partitions ** (with A. M. Garsia),
* Adv. in Math.* 31
(1979), 288–305.

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**Generating Functions and Enumeration of Sequences,**
Ph.D. Thesis, Massachusetts Institute of Technology, 1977.

pdf file