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 A185777 #7 Jul 22 2025 10:00:23 %S A185777 81,558,558,3844,7074,3844,26784,89118,89118,26784,186624,1151346, %T A185777 2046098,1151346,186624,1296000,14837270,48744342,48744342,14837270, %U A185777 1296000,9000000,190416934,1154712762,2171002788,1154712762,190416934 %N A185777 T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with no 2X2 subblock sum equal to any horizontal or vertical neighbor 2X2 subblock sum. %C A185777 Table starts %C A185777 .........81..........558...........3844...........26784..........186624 %C A185777 ........558.........7074..........89118.........1151346........14837270 %C A185777 .......3844........89118........2046098........48744342......1154712762 %C A185777 ......26784......1151346.......48744342......2171002788.....95851024672 %C A185777 .....186624.....14837270.....1154712762.....95851024672...7861640359954 %C A185777 ....1296000....190416934....27239862108...4212755548948.641850855452998 %C A185777 ....9000000...2442333998...641595944400.184696487434352 %C A185777 ...62568000..31384892214.15156754839024 %C A185777 ..434972736.403218559222 %C A185777 .3022785216 %H A185777 R. H. Hardin, <a href="/A185777/b185777.txt">Table of n, a(n) for n = 1..59</a> %e A185777 Some solutions for 4X3 %e A185777 ..1..2..0....0..2..1....1..1..1....0..2..1....0..0..1....1..2..0....2..2..0 %e A185777 ..2..0..1....0..1..1....0..2..1....0..2..2....1..1..2....0..0..0....0..0..1 %e A185777 ..1..0..1....0..0..2....0..0..0....0..0..0....0..2..1....1..0..0....2..1..0 %e A185777 ..2..2..0....0..0..1....2..1..0....2..2..0....0..1..0....1..1..1....1..2..0 %K A185777 nonn,tabl %O A185777 1,1 %A A185777 _R. H. Hardin_ Feb 03 2011