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 A231266 #6 Jul 23 2025 06:21:35 %S A231266 86,547,2982,19503,126851,866396,5921588,40973953,283765581, %T A231266 1972122444,13710377266,95395947525,663770545015,4619277813951, %U A231266 32145505935933,223706188296535,1556796061665136,10833978133171498,75395132198062729 %N A231266 Number of (4+1)X(n+1) 0..2 arrays with no element unequal to a strict majority of its horizontal and antidiagonal neighbors, with values 0..2 introduced in row major order. %C A231266 Row 4 of A231263 %H A231266 R. H. Hardin, <a href="/A231266/b231266.txt">Table of n, a(n) for n = 1..210</a> %e A231266 Some solutions for n=3 %e A231266 ..0..0..0..0....0..0..0..0....0..0..1..1....0..0..0..0....0..0..1..1 %e A231266 ..0..0..1..1....1..1..0..0....0..1..1..1....0..0..0..0....0..1..1..2 %e A231266 ..1..1..2..2....1..2..2..2....1..1..1..1....0..0..0..1....1..1..2..2 %e A231266 ..1..2..1..1....2..1..1..0....1..1..2..2....0..0..1..1....1..2..0..0 %e A231266 ..2..1..1..1....1..1..0..0....1..2..2..2....0..0..0..0....2..0..0..0 %K A231266 nonn %O A231266 1,1 %A A231266 _R. H. Hardin_, Nov 06 2013