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 A198722 #9 Mar 12 2023 14:16:02 %S A198722 203,7817980,846047363854,96356630422085931,10996875674843226590993, %T A198722 1255145613308486512244031328,143258513960209594417739070314380, %U A198722 16351094722174331189725220168411285754,1866264648662016827992654208819869556160352 %N A198722 Number of n X 7 0..6 arrays with values 0..6 introduced in row major order and no element equal to any horizontal or vertical neighbor. %H A198722 Andrew Howroyd, <a href="/A198722/b198722.txt">Table of n, a(n) for n = 1..200</a> %e A198722 Some solutions with all values 0 to 6 for n=3: %e A198722 0 1 0 2 3 4 5 0 1 0 2 1 3 0 0 1 0 2 0 1 3 %e A198722 1 0 1 0 2 6 4 1 0 1 0 4 0 2 1 0 1 0 4 5 1 %e A198722 0 1 0 3 6 0 2 0 1 0 3 5 3 6 0 1 0 3 6 1 2 %Y A198722 Column 7 of A198723. %K A198722 nonn %O A198722 1,1 %A A198722 _R. H. Hardin_, Oct 29 2011 %E A198722 Terms a(7) and beyond from _Andrew Howroyd_, Mar 12 2023