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 A206860 #7 Jul 22 2025 19:44:03 %S A206860 191,36481,3425501,314918295,31208037240,3092914364659, %T A206860 303316860005399,29725367062521082,2918687692387968133, %U A206860 286698257332823360369,28152247554788869997756,2763985738207647315882808 %N A206860 Number of nX5 0..2 arrays avoiding the pattern z z+1 z in any row, column, diagonal or antidiagonal. %C A206860 Column 5 of A206863 %H A206860 R. H. Hardin, <a href="/A206860/b206860.txt">Table of n, a(n) for n = 1..210</a> %e A206860 Some solutions for n=4 %e A206860 ..0..2..2..0..0....1..2..2..1..2....1..0..0..0..0....1..2..2..1..1 %e A206860 ..1..0..1..1..2....0..1..1..2..2....1..2..2..0..0....1..1..0..1..2 %e A206860 ..2..2..1..2..2....1..0..1..2..0....2..0..0..2..1....1..2..0..1..2 %e A206860 ..2..1..2..2..2....1..1..2..0..2....2..1..1..1..1....1..2..0..0..1 %K A206860 nonn %O A206860 1,1 %A A206860 _R. H. Hardin_ Feb 13 2012