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 A281603 #4 Jan 25 2017 10:39:31 %S A281603 82,1708,49572,1626073,52899445,1732267694,56764280423,1860912910152, %T A281603 61012156448915,2000405755119383,65587722113126449, %U A281603 2150442541118935258,70507185356580640501,2311739967430549263763,75795706200446791975455 %N A281603 Number of nX6 0..2 arrays with no element equal to more than one of its horizontal, diagonal or antidiagonal neighbors and with new values introduced in order 0 sequentially upwards. %C A281603 Column 6 of A281605. %H A281603 R. H. Hardin, <a href="/A281603/b281603.txt">Table of n, a(n) for n = 1..210</a> %e A281603 Some solutions for n=3 %e A281603 ..0..1..0..2..1..0. .0..1..2..1..0..1. .0..1..0..1..2..0. .0..1..1..0..1..1 %e A281603 ..0..2..1..0..1..0. .0..1..0..1..0..2. .2..2..0..1..0..2. .0..2..2..0..2..0 %e A281603 ..2..0..1..2..1..2. .0..1..2..1..2..1. .1..1..0..1..0..1. .0..1..0..1..2..1 %Y A281603 Cf. A281605. %K A281603 nonn %O A281603 1,1 %A A281603 _R. H. Hardin_, Jan 25 2017