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 A264841 #23 Feb 25 2016 03:13:28 %S A264841 1,2,12,4,74,1442,8,456,28028,1716098,16,2810,544844,105093828, %T A264841 20276816980,32,17316,10591310,6435880414,3912156203494, %U A264841 2378025136264102,64,106706,205886234,394129505248,754801786191820,1445496758320387318,2768227968406304217000,128,657552,4002256640,24136256828880 %N A264841 Triangle read by rows: T(n,k) is the number of ways to partition an n X k square grid into any number of parts along the gridlines. %C A264841 A set of edges forms a valid partition if and only if it includes the entire boundary of the grid, and there are no vertices of degree 1. %H A264841 Danny Rorabaugh, <a href="/A264841/a264841.pdf">A264841 Example: T(2,2)</a> %H A264841 R. J. Mathar, <a href="http://www.vixra.org/abs/1511.0225">Counting 2-way monotonic terrace forms over rectangular landscapes</a>, see Section 6.3, Combinatorics and Graph Theory, viXra:1511.0225, 2015. %F A264841 T(n,1) = 2^(n-1). %F A264841 T(n,2) = A078469(n). %e A264841 The triangle T(n,k) begins: %e A264841 n\k 1 2 3 4 5 %e A264841 1: 1 %e A264841 2: 2 12 %e A264841 3: 4 74 1442 %e A264841 4: 8 456 28028 1716098 %e A264841 5: 16 2810 544844 105093828 20276816980 %Y A264841 A078469 is the second column of this triangle. %K A264841 nonn,tabl %O A264841 1,2 %A A264841 _Linus Hamilton_, Nov 26 2015