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 A267748 #10 Sep 07 2023 19:50:04 %S A267748 1,10,39,118,313,780,1789,4024,8793,18760,39577,82662,170677,350758, %T A267748 717189,1458604,2959003,5987586 %N A267748 Number of n X 3 arrays containing 3 copies of 0..n-1 with every element equal to or 1 greater than any north neighbor modulo n and the upper left element equal to 0. %e A267748 Some solutions for n=4: %e A267748 ..0..0..2....0..3..2....0..1..1....0..3..3....0..2..2....0..1..3....0..2..0 %e A267748 ..1..1..3....0..3..2....1..2..2....1..0..0....1..3..2....1..2..3....1..3..1 %e A267748 ..2..1..3....1..0..2....2..3..3....2..1..1....1..3..3....2..3..0....2..3..1 %e A267748 ..3..2..0....1..1..3....3..0..0....3..2..2....1..0..0....2..0..1....3..0..2 %Y A267748 Column 3 of A267751. %K A267748 nonn,more %O A267748 1,2 %A A267748 _R. H. Hardin_, Jan 20 2016