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 A198981 #6 Jul 22 2025 13:07:58 %S A198981 202,3603244,98102456246,2692353648978984,73900197917712351603, %T A198981 2028430770889558380053172,55676868201599759013090066735, %U A198981 1528232414884966866457407229662199 %N A198981 Number of nX7 0..5 arrays with values 0..5 introduced in row major order and no element equal to any horizontal or vertical neighbor. %C A198981 Column 7 of A198982 %e A198981 Some solutions with all values from 0 to 5 for n=4 %e A198981 ..0..1..0..1..0..1..2....0..1..0..1..0..2..0....0..1..0..1..0..2..1 %e A198981 ..1..0..1..0..3..2..4....1..0..1..0..3..0..4....1..0..1..0..3..4..5 %e A198981 ..0..3..0..1..0..4..0....0..3..0..1..2..4..0....0..3..0..1..0..1..4 %e A198981 ..3..0..1..0..5..3..5....3..0..1..0..4..5..4....3..0..1..0..1..5..3 %K A198981 nonn %O A198981 1,1 %A A198981 _R. H. Hardin_ Nov 01 2011