This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A255539 #29 Oct 23 2022 23:32:58 %S A255539 1,1,1,3,4,10,19,51,112,300,746,2042,5450,15197,42192,119561,339594 %N A255539 Number of digital images in Z^2 with 4-adjacency on n points up to isomorphism. %C A255539 Also the number of polyominoes on n points, up to isomorphism of the adjacency graph. %C A255539 Also the number of "grid graphs" (finite induced subgraphs of the integer lattice using only horizontal and vertical edges) on n vertices. %H A255539 P. Christopher Staecker, <a href="http://arxiv.org/abs/1502.06236">Some enumerations of binary digital images</a>, arXiv 1502.06236 [math.CO], 2015. %H A255539 Baoming Tang, Ehsan Khatami and Marcos Rigol, <a href="https://doi.org/10.1016/j.cpc.2012.10.008">A short introduction to numerical linked-cluster expansions</a>, Computer Physics Communications, 184 (2013), 557-564; arXiv:<a href="https://arxiv.org/abs/1207.3366">1207.3366</a> [cond-mat.stat-mech], 2012. %e A255539 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. %Y A255539 Cf. A000105, A181528, A255540. %K A255539 nonn,more,hard %O A255539 1,4 %A A255539 _P. Christopher Staecker_, Feb 24 2015 %E A255539 a(13)-a(16) from _Giovanni Resta_, Apr 10 2020 %E A255539 a(17) from Tang et al. added by _Andrey Zabolotskiy_, Oct 23 2022