A255539 Number of digital images in Z^2 with 4-adjacency on n points up to isomorphism.
1, 1, 1, 3, 4, 10, 19, 51, 112, 300, 746, 2042, 5450, 15197, 42192, 119561, 339594
Offset: 1
Examples
a(4) = 3: (1) the square tetromino has the 4-cycle as its "adjacency graph"; (2) the T-tetromino corresponds to the claw graph; (3) the straight, skew, and L-tetromino all correspond to the 4-path.
Links
- P. Christopher Staecker, Some enumerations of binary digital images, arXiv 1502.06236 [math.CO], 2015.
- Baoming Tang, Ehsan Khatami and Marcos Rigol, A short introduction to numerical linked-cluster expansions, Computer Physics Communications, 184 (2013), 557-564; arXiv:1207.3366 [cond-mat.stat-mech], 2012.
Extensions
a(13)-a(16) from Giovanni Resta, Apr 10 2020
a(17) from Tang et al. added by Andrey Zabolotskiy, Oct 23 2022
Comments