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 A350030 #20 Dec 11 2021 02:18:37 %S A350030 1,1,2,4,11,27,82,250,815,2685,9072,30889,106290,367733,1279573, %T A350030 4470304,15676760,55147665 %N A350030 a(n) is the number of n-celled unholey treelike polyominoes. %F A350030 a(n) = A308300(n,0). %Y A350030 Cf. A308300 (number of simply connected square animals with n cells and k internal vertices, triangle read by rows). %Y A350030 Cf. A131482 (polyominoes with perimeter 2n+2, i.e., treelike). %K A350030 nonn,hard,more %O A350030 1,3 %A A350030 _John Mason_, Dec 09 2021