M. Abrahamsen and S. Eilers, On the Asymptotic Enumeration of LEGO Structures, Experimental Mathematics, vol.20, issue.2
DOI : 10.1007/BF02183684

M. Abrahamsen and S. Eilers, Efficient counting of LEGO buildings

E. Barcucci, A. Del-lungo, E. Pergola, and R. Pinzani, Directed animals, forests and permutations, Discrete Mathematics, vol.204, issue.1-3, pp.103-117, 1999.
DOI : 10.1016/S0012-365X(98)00366-5

URL : http://doi.org/10.1016/s0012-365x(98)00366-5

J. Bétréma and J. Penaud, Animaux et arbres guingois, Theoretical Computer Science, vol.117, issue.1-2, pp.67-89, 1993.
DOI : 10.1016/0304-3975(93)90304-C

J. Bétréma and J. Penaud, Modèles avec particules dures, animaux dirigés et séries en variables partiellement commutatives, 1993.

M. Bousquet-mélou and A. Rechnitzer, Lattice animals and heaps of dimers, Discrete Mathematics, vol.258, issue.1-3, pp.235-274, 2002.
DOI : 10.1016/S0012-365X(02)00352-7

N. T. Cameron, The combinatorics of even trees, Proc. of the 31. Southeastern International Conf. on Combinatorics, Graph theory and Computing, pp.129-143, 2000.

N. T. Cameron, Random Walks, Trees and Extensions of Riordan Group Techniques, Annual Joint Mathematics Meetings, 2003.

A. R. Conway and A. J. Guttmann, On two-dimensional percolation, Journal of Physics A: Mathematical and General, vol.28, issue.4, pp.891-904, 1995.
DOI : 10.1088/0305-4470/28/4/015

D. Dhar, Equivalence of the Two-Dimensional Directed-Site Animal Problem to Baxter's Hard-Square Lattice-Gas Model, Physical Review Letters, vol.49, issue.14, pp.959-962, 1982.
DOI : 10.1103/PhysRevLett.49.959

B. Durhuus and S. Eilers, On the entropy of LEGO ??, Journal of Applied Mathematics and Computing, vol.576, issue.1-2, p.504039, 2005.
DOI : 10.1007/s12190-013-0730-9

P. Flajolet and R. Sedgewick, Analytic Combinatorics, 2009.
DOI : 10.1017/CBO9780511801655

URL : https://hal.archives-ouvertes.fr/inria-00072739

G. Grimmett, Percolation, Grundlehren der mathematischen Wissenschaften, vol.321, 1999.

D. Gouyou-beauchamps and G. Viennot, Equivalence of the two-dimensional directed animal problem to a one-dimensional path problem, Advances in Applied Mathematics, vol.9, issue.3, pp.334-357, 1988.
DOI : 10.1016/0196-8858(88)90017-6

V. Hakim and J. Nadal, Exact results for 2D directed animals on a strip of finite width, Journal of Physics A: Mathematical and General, vol.16, issue.7, pp.213-218, 1983.
DOI : 10.1088/0305-4470/16/7/003

D. A. Klarner, Some results concerning polyominoes, Fibonacci Quart, vol.3, pp.9-20, 1965.

D. A. Klarner and R. L. Rivest, A procedure for improving the upper bound for the number of $n$-ominoes, Journal canadien de math??matiques, vol.25, issue.0, pp.25-585, 1973.
DOI : 10.4153/CJM-1973-060-4

L. Gall, Random trees and applications, Probability Surveys, vol.2, issue.0, pp.245-311, 2005.
DOI : 10.1214/154957805100000140

J. Penaud, Une nouvelle bijection pour les animaux dirigés, Actes du 22ème séminaire lotharingen de combinatoire, 1989.

L. W. Shapiro, Directed animals and Motzkin paths, 1999.

N. J. Sloane, The Online Encyclopaedia of Integer Sequences

H. N. Temperley, Combinatorial problems suggested by the statistial mechanics of domains and of rubber-like molecules, Phys. Rev, vol.101, pp.1-16, 1956.

G. X. Viennot, Probì emes combinatoires posès par la physique statistique, pp.121-122, 1985.

G. X. Viennot, Heaps of pieces, I : Basic definitions and combinatorial lemmas, Lecture Notes in Mathematics, vol.56, pp.321-350, 1986.
DOI : 10.1016/0012-365X(85)90192-X

D. Zeilberger, Automated counting of lego towers, Journal of Difference Equations and Applications, vol.626, issue.4-5, pp.323-333, 1999.
DOI : 10.1103/PhysRev.103.1