A066158 Number of fixed polyominoes with n cells and tree-like structure.
1, 2, 6, 18, 55, 174, 570, 1908, 6473, 22202, 76886, 268352, 942651, 3329608, 11817582, 42120340, 150682450, 540832274, 1946892842, 7027047848, 25424079339, 92185846608, 334925007128, 1219054432490, 4444545298879, 16229462702152, 59347661054364
Offset: 1
References
- G. Aleksandrowicz and G. Barequet, Parallel enumeration of lattice animals, Proc. 5th Int. Frontiers of Algorithmics Workshop, Zhejiang, China, Lecture Notes in Computer Science, 6681, Springer-Verlag, 90-99, May 2011.
- N. Madras, C. E. Soteros, S. G. Whittington, J. L. Martin, M. F. Sykes et al., The free energy of a collapsing branched polymer, J. Phys. A: Math. Gen. 23 (1990) 5327-5350.
Links
- I. Jensen, Table of n, a(n) for n = 1..44 [From the arXiv paper]
- Gill Barequet, Gil Ben-Shachar, Martha Carolina Osegueda, Applications of Concatenation Arguments to Polyominoes and Polycubes, EuroCG '20, 36th European Workshop on Computational Geometry, (Würzburg, Germany, 16-18 March 2020).
- I. Jensen, Enumerations of lattice animals and trees, J. Stat. Phys. 103 (3-4) (2001) 865-881, Table II.
- I. Jensen, Enumerations of lattice animals and trees, arXiv:cond-mat/0007239.
Crossrefs
Extensions
Added a(18) and a(19) from Madras et al. - R. J. Mathar, Apr 08 2006
Terms from a(20) on added by N. J. A. Sloane, Nov 05 2008, from the Jensen paper.
Comments