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 A302889 #4 Apr 15 2018 10:50:18 %S A302889 1,1,2,1,2,4,1,12,2,8,1,20,37,3,16,1,72,53,141,6,32,1,168,197,238,569, %T A302889 10,64,1,496,818,2278,1102,2262,21,128,1,1296,2548,12782,20937,5570, %U A302889 8968,42,256,1,3616,10926,98458,200186,206332,28594,35667,86,512,1,9760,42671 %N A302889 T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 2, 3, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A302889 Table starts %C A302889 ...1..1......1......1.........1...........1.............1...............1 %C A302889 ...2..2.....12.....20........72.........168...........496............1296 %C A302889 ...4..2.....37.....53.......197.........818..........2548...........10926 %C A302889 ...8..3....141....238......2278.......12782.........98458..........714934 %C A302889 ..16..6....569...1102.....20937......200186.......2727690........37626360 %C A302889 ..32.10...2262...5570....206332.....3452246......89290791......2247650354 %C A302889 ..64.21...8968..28594...2059835....60501563....2899297652....133518102376 %C A302889 .128.42..35667.149206..20622709..1073161270...94799190457...7977498513759 %C A302889 .256.86.141839.788373.206851726.19073141368.3098646840396.476377988322833 %H A302889 R. H. Hardin, <a href="/A302889/b302889.txt">Table of n, a(n) for n = 1..180</a> %F A302889 Empirical for column k: %F A302889 k=1: a(n) = 2*a(n-1) %F A302889 k=2: a(n) = 2*a(n-1) +a(n-2) -a(n-3) -2*a(n-4) +a(n-5) %F A302889 k=3: [order 10] %F A302889 k=4: [order 35] for n>37 %F A302889 Empirical for row n: %F A302889 n=1: a(n) = a(n-1) %F A302889 n=2: a(n) = 2*a(n-1) +4*a(n-2) -4*a(n-3) -4*a(n-4) %F A302889 n=3: [order 16] for n>17 %F A302889 n=4: [order 51] for n>54 %e A302889 Some solutions for n=5 k=4 %e A302889 ..0..1..1..0. .0..1..1..1. .0..1..1..0. .0..0..0..0. .0..1..1..0 %e A302889 ..1..1..1..0. .1..1..1..0. .0..1..1..0. .1..0..0..1. .0..1..1..1 %e A302889 ..0..1..1..0. .0..1..1..0. .0..1..1..1. .1..0..0..1. .0..1..1..1 %e A302889 ..0..1..1..0. .0..1..1..1. .1..1..1..0. .0..0..0..0. .1..1..1..0 %e A302889 ..0..1..1..1. .0..1..1..0. .0..1..1..1. .0..0..0..1. .1..1..1..0 %Y A302889 Column 1 is A000079(n-1). %Y A302889 Column 2 is A240513(n-2). %Y A302889 Row 2 is A302368. %K A302889 nonn,tabl %O A302889 1,3 %A A302889 _R. H. Hardin_, Apr 15 2018