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 A280671 #4 Jan 07 2017 08:05:52 %S A280671 82,10893,1401470,183331502,23952262535,3130289979912,409089889172506, %T A280671 53463025958093933,6986960714513387194,913109939977637081743, %U A280671 119332252787740585439815,15595259598595853987150831 %N A280671 Number of nX6 0..2 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards. %C A280671 Column 6 of A280673. %H A280671 R. H. Hardin, <a href="/A280671/b280671.txt">Table of n, a(n) for n = 1..210</a> %F A280671 Empirical: a(n) = 115*a(n-1) +2093*a(n-2) -4155*a(n-3) -183686*a(n-4) -585648*a(n-5) +633260*a(n-6) +10692868*a(n-7) -4449787*a(n-8) -90326895*a(n-9) -58218792*a(n-10) -85358831*a(n-11) -153604102*a(n-12) +506925527*a(n-13) +114376456*a(n-14) +783370521*a(n-15) +27819835*a(n-16) +40476932*a(n-17) -4134454*a(n-18) +1119384*a(n-19) -261121*a(n-20) for n>22 %e A280671 Some solutions for n=2 %e A280671 ..0..1..2..0..2..1. .0..1..0..1..0..1. .0..0..1..0..2..2. .0..0..1..0..1..0 %e A280671 ..0..1..1..0..2..2. .1..2..2..0..2..1. .2..2..1..1..0..0. .2..2..0..1..0..2 %Y A280671 Cf. A280673. %K A280671 nonn %O A280671 1,1 %A A280671 _R. H. Hardin_, Jan 07 2017