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 A229409 #6 Jul 23 2025 05:43:25 %S A229409 819,199595,49788258,12462062342,3113479414050,777638567093963, %T A229409 194334416016079648,48554820719187209670,12132494321992628909959, %U A229409 3031488710689140016181815,757470261215571296326841223 %N A229409 Number of nX5 0..3 arrays avoiding 11 horizontally, 22 vertically, 33 antidiagonally and 00 diagonally. %C A229409 Column 5 of A229412 %H A229409 R. H. Hardin, <a href="/A229409/b229409.txt">Table of n, a(n) for n = 1..210</a> %e A229409 Some solutions for n=3 %e A229409 ..0..0..1..3..2....0..0..2..0..0....0..0..0..3..1....0..0..0..3..2 %e A229409 ..0..2..1..2..1....0..2..1..0..3....0..2..1..3..2....0..2..1..2..1 %e A229409 ..0..3..1..0..3....2..3..2..0..2....0..1..2..1..0....1..3..0..1..2 %K A229409 nonn %O A229409 1,1 %A A229409 _R. H. Hardin_ Sep 22 2013