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 A377941 #26 Feb 14 2025 10:49:57 %S A377941 1,0,1,0,1,1,0,2,2,1,0,1,8,2,1,0,1,17,13,3,1,0,1,39,45,19,3,1,0,1,79, %T A377941 182,77,25,4,1,0,1,162,607,363,114,33,4,1,0,1,301,2004,1539,593,170, %U A377941 41,5,1,0,1,589,6139,6361,2764,928,234,51,5,1,0,1,1141,18278,25072,12733,4597,1387,323,61,6,1 %N A377941 Triangle read by rows: T(n,k) = number of free polyominoes with n cells, where the maximum number of cells in any row or column is k. %C A377941 The row sum are the total number of polyominoes with n cells. %H A377941 John Mason, <a href="/A377941/b377941.txt">Table of n, a(n) for n = 1..153</a> (17 rows) %H A377941 Dave Budd, <a href="https://github.com/daveisagit/oeis/blob/main/square_lattice/connected_nodes.py">Python code for a square lattice</a> %e A377941 | k %e A377941 n | 1 2 3 4 5 6 7 8 9 10 Total %e A377941 ---------------------------------------------------------------------------------- %e A377941 1 | 1 1 %e A377941 2 | 0 1 1 %e A377941 3 | 0 1 1 2 %e A377941 4 | 0 2 2 1 5 %e A377941 5 | 0 1 8 2 1 12 %e A377941 6 | 0 1 17 13 3 1 35 %e A377941 7 | 0 1 39 45 19 3 1 108 %e A377941 8 | 0 1 79 182 77 25 4 1 369 %e A377941 9 | 0 1 162 607 363 114 33 4 1 1285 %e A377941 10 | 0 1 301 2004 1539 593 170 41 5 1 4655 %e A377941 ... %e A377941 The T(4,2)=2 polyominoes are: %e A377941 * * * * %e A377941 * * * * %Y A377941 Row sums are A000105. %Y A377941 Cf. A377942. %K A377941 nonn,tabl %O A377941 1,8 %A A377941 _Dave Budd_, Nov 11 2024 %E A377941 More terms from _Pontus von Brömssen_, Nov 12 2024