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 A189603 #8 Apr 16 2023 20:07:55 %S A189603 1,3,20,464,30283,5897476,3394457868,5778059258273,29117129479453520, %T A189603 434446215594380010575 %N A189603 Number of n X n array permutations with each element not moving, or moving one space E, S or NW. %C A189603 Diagonal of A189610. %e A189603 Some solutions for 3 X 3 %e A189603 ..4..1..2....0..1..2....4..0..2....4..0..1....4..0..2....0..1..2....4..1..2 %e A189603 ..0..8..5....3..8..4....7..1..5....7..8..2....3..1..5....7..8..4....0..3..5 %e A189603 ..3..6..7....6..7..5....3..6..8....3..6..5....6..7..8....3..6..5....6..7..8 %Y A189603 Cf. A189610. %K A189603 nonn %O A189603 1,2 %A A189603 _R. H. Hardin_, Apr 24 2011