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 A222912 #5 Jul 23 2025 03:15:10 %S A222912 715,15919,759891,105327353,4854855483,997770825049,51666240687220, %T A222912 11720702848290810,667162032011395790,166939045536469920335 %N A222912 Number of 7Xn 0..3 arrays with no more than floor(7Xn/2) elements unequal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..3 order. %C A222912 Row 7 of A222906 %e A222912 Some solutions for n=3 %e A222912 ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0 %e A222912 ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0 %e A222912 ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0 %e A222912 ..0..0..1....0..1..1....0..0..1....0..0..1....0..0..0....0..0..1....0..1..0 %e A222912 ..1..2..1....2..1..1....1..2..0....1..0..0....1..2..2....2..2..0....2..1..1 %e A222912 ..2..0..0....3..0..0....2..2..3....2..0..0....3..1..1....2..2..0....1..1..1 %e A222912 ..3..0..3....0..0..1....3..3..1....3..0..0....0..1..2....2..3..1....3..2..2 %K A222912 nonn %O A222912 1,1 %A A222912 _R. H. Hardin_ Mar 09 2013