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 A280065 #4 Dec 25 2016 06:38:25 %S A280065 2,4,15,52,170,603,2157,7777,28195,102429,372430,1355019,4930977, %T A280065 17946466,65320396,237756751,865411414,3150039989,11465974491, %U A280065 41735611962,151915810407,552967220870,2012778077066,7326430841669 %N A280065 Number of nX4 0..1 arrays with no element unequal to a strict majority of its horizontal, vertical and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards. %C A280065 Column 4 of A280069. %H A280065 R. H. Hardin, <a href="/A280065/b280065.txt">Table of n, a(n) for n = 1..210</a> %F A280065 Empirical: a(n) = 4*a(n-1) +4*a(n-2) -21*a(n-3) -4*a(n-4) +34*a(n-5) +25*a(n-6) -37*a(n-7) -82*a(n-8) +44*a(n-9) +36*a(n-10) +6*a(n-11) -a(n-12) -5*a(n-13) -3*a(n-14) +a(n-15) for n>18 %e A280065 Some solutions for n=4 %e A280065 ..0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..1..1. .0..0..0..0 %e A280065 ..0..0..0..1. .0..0..0..1. .0..0..0..1. .0..0..1..1. .0..0..0..1 %e A280065 ..0..1..1..1. .1..1..1..1. .0..0..1..1. .0..1..1..1. .0..0..1..1 %e A280065 ..1..1..1..1. .1..1..1..1. .0..1..1..1. .1..1..1..1. .0..0..1..1 %Y A280065 Cf. A280069. %K A280065 nonn %O A280065 1,1 %A A280065 _R. H. Hardin_, Dec 25 2016