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 A302367 #4 Apr 06 2018 12:21:15 %S A302367 1,1,2,1,2,4,1,12,2,8,1,20,31,3,16,1,72,20,109,6,32,1,168,154,77,397, %T A302367 10,64,1,496,284,918,209,1430,21,128,1,1296,1109,3125,6580,774,5110, %U A302367 42,256,1,3616,3472,21831,26458,49293,3143,18395,86,512,1,9760,12763,125193 %N A302367 T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 2, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A302367 Table starts %C A302367 ...1..1.....1.....1........1.........1...........1.............1 %C A302367 ...2..2....12....20.......72.......168.........496..........1296 %C A302367 ...4..2....31....20......154.......284........1109..........3472 %C A302367 ...8..3...109....77......918......3125.......21831........125193 %C A302367 ..16..6...397...209.....6580.....26458......405340.......3462040 %C A302367 ..32.10..1430...774....49293....330505.....9361759.....134269527 %C A302367 ..64.21..5110..3143...367512...3858625...188443738....4558781926 %C A302367 .128.42.18395.13556..2856621..48375470..4174802035..169314399506 %C A302367 .256.86.66203.60280.22185382.608124211.91302504318.6186362081201 %H A302367 R. H. Hardin, <a href="/A302367/b302367.txt">Table of n, a(n) for n = 1..180</a> %F A302367 Empirical for column k: %F A302367 k=1: a(n) = 2*a(n-1) %F A302367 k=2: a(n) = 2*a(n-1) +a(n-2) -a(n-3) -2*a(n-4) +a(n-5) %F A302367 k=3: [order 12] %F A302367 k=4: [order 50] for n>53 %F A302367 Empirical for row n: %F A302367 n=1: a(n) = a(n-1) %F A302367 n=2: a(n) = 2*a(n-1) +4*a(n-2) -4*a(n-3) -4*a(n-4) %F A302367 n=3: [order 16] for n>18 %F A302367 n=4: [order 63] for n>66 %e A302367 Some solutions for n=5 k=4 %e A302367 ..0..1..1..0. .0..1..1..0. .0..0..1..0. .0..0..1..1. .0..1..1..0 %e A302367 ..1..1..1..1. .0..1..1..0. .0..0..1..0. .0..0..1..1. .1..1..1..1 %e A302367 ..0..1..0..0. .1..1..1..1. .0..1..1..1. .0..1..1..0. .1..1..0..0 %e A302367 ..0..1..0..0. .0..0..0..0. .0..0..0..0. .0..0..1..1. .1..1..0..0 %e A302367 ..0..1..0..0. .0..0..0..1. .1..0..0..1. .0..0..1..1. .1..1..0..0 %Y A302367 Column 1 is A000079(n-1). %Y A302367 Column 2 is A240513(n-2). %K A302367 nonn,tabl %O A302367 1,3 %A A302367 _R. H. Hardin_, Apr 06 2018