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 A199126 #9 Jul 22 2025 13:10:37 %S A199126 1,1,1,3,6,5,19,37,29,124,240,182,834,1614,1198,5746,11137,8142,40336, %T A199126 78332,56620,287358,559134,400598,2071558,4038130,2872754,15079270, %U A199126 29443040,20824778,110653854,216379650,152303410,817542980,1600817660 %N A199126 Number of nX1 0..2 arrays with values 0..2 introduced in row major order, the number of instances of each value within one of each other, and no element equal to any horizontal or vertical neighbor. %C A199126 Column 1 of A199133 %H A199126 R. H. Hardin, <a href="/A199126/b199126.txt">Table of n, a(n) for n = 1..200</a> %F A199126 Conjecture: a(3n) = A190917(n). - _R. J. Mathar_, Nov 01 2015 %e A199126 All solutions for n=5 %e A199126 ..0....0....0....0....0....0 %e A199126 ..1....1....1....1....1....1 %e A199126 ..2....2....2....0....2....0 %e A199126 ..0....1....0....2....1....1 %e A199126 ..2....2....1....1....0....2 %K A199126 nonn %O A199126 1,4 %A A199126 _R. H. Hardin_ Nov 03 2011