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 A268159 #6 Aug 12 2016 06:55:35 %S A268159 0,0,0,0,1,0,0,1,0,0,0,3,8,6,0,0,7,14,36,0,0,0,17,52,906,456,120,0,0, %T A268159 42,1516,31818,23592,6360,0,0,0,104,7582,770406,10213152,3304920, %U A268159 93600,5040,0,0,259,46338,28194516,871718016,4067565720,334738800,1784160,0,0,0,648 %N A268159 T(n,k)=Number of nXk arrays containing k copies of 0..n-1 with every element equal to at least one vertical or antidiagonal neighbor and the top left element equal to 0. %C A268159 Table starts %C A268159 .0....0.......0.........0..........0.............0............0.........0 %C A268159 .0....1.......1.........3..........7............17...........42.......104 %C A268159 .0....0.......8........14.........52..........1516.........7582.....46338 %C A268159 .0....6......36.......906......31818........770406.....28194516.857204082 %C A268159 .0....0.....456.....23592...10213152.....871718016.131259920304 %C A268159 .0..120....6360...3304920.4067565720.2310125813160 %C A268159 .0....0...93600.334738800 %C A268159 .0.5040.1784160 %C A268159 .0....0 %C A268159 .0 %H A268159 R. H. Hardin, <a href="/A268159/b268159.txt">Table of n, a(n) for n = 1..61</a> %e A268159 Some solutions for n=4 k=4 %e A268159 ..0..3..3..1....0..3..2..3....0..3..1..2....0..2..1..2....0..0..1..1 %e A268159 ..0..3..2..1....0..3..2..3....0..3..1..2....0..2..1..2....0..1..2..1 %e A268159 ..3..2..0..1....1..1..0..2....3..0..2..1....1..3..0..3....0..2..3..3 %e A268159 ..2..2..0..1....1..1..0..2....3..0..2..1....1..3..0..3....2..2..3..3 %Y A268159 Column 2 is A005212(n-1). %Y A268159 Row 2 is A003440(n-2). %K A268159 nonn,tabl %O A268159 1,12 %A A268159 _R. H. Hardin_, Jan 27 2016