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 A285750 #6 Apr 05 2020 20:11:25 %S A285750 0,0,0,1,4,0,2,8,14,0,6,44,105,52,0,12,150,630,550,206,0,28,540,4850, %T A285750 8544,5105,772,0,56,2042,31276,119506,125088,30918,2896,0,119,7760, %U A285750 250592,1729212,3640966,1835412,265920,10996,0,236,29654,1727836 %N A285750 T(n,k) = Number of n X k 0..1 arrays with the number of 1's horizontally, diagonally or antidiagonally adjacent to some 0 one less than the number of 0's adjacent to some 1. %C A285750 Table starts %C A285750 .0.....0........1..........2.............6...............12.................28 %C A285750 .0.....4........8.........44...........150..............540...............2042 %C A285750 .0....14......105........630..........4850............31276.............250592 %C A285750 .0....52......550.......8544........119506..........1729212...........25450414 %C A285750 .0...206.....5105.....125088.......3640966.........99685406.........3020617824 %C A285750 .0...772....30918....1835412.....101515318.......5826888288.......341001631140 %C A285750 .0..2896...265920...27339964....3077883556.....345505561776.....40895629554933 %C A285750 .0.10996..1773432..410644956...90409954434...20683003285236...4828422171183992 %C A285750 .0.41862.14632372.6209001966.2751592992660.1247496214559062.584834466962677402 %H A285750 R. H. Hardin, <a href="/A285750/b285750.txt">Table of n, a(n) for n = 1..143</a> %e A285750 Some solutions for n=4, k=4 %e A285750 ..0..0..0..0. .0..1..1..1. .0..1..1..1. .0..0..0..1. .0..0..0..0 %e A285750 ..1..0..1..0. .0..1..0..0. .1..0..0..0. .1..1..1..0. .1..0..1..1 %e A285750 ..1..0..0..1. .1..0..0..1. .0..0..0..0. .0..1..0..1. .1..0..1..1 %e A285750 ..1..1..0..0. .1..0..0..0. .1..0..0..0. .1..0..0..0. .0..1..0..0 %Y A285750 Column 2 is A284765. %Y A285750 Row 1 is A284449. %K A285750 nonn,tabl %O A285750 1,5 %A A285750 _R. H. Hardin_, Apr 25 2017