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 A206956 #7 Jul 22 2025 19:50:10 %S A206956 1465,2146225,1455935650,950821989599,656572043220119, %T A206956 455424052435622710,314368117565737962789,216873306373656734739325, %U A206956 149694579632520898257449851,103334879849813837848577474301 %N A206956 Number of nX7 0..2 arrays avoiding the pattern z z+1 z in any row, column or nw-to-se diagonal. %C A206956 Column 7 of A206957 %H A206956 R. H. Hardin, <a href="/A206956/b206956.txt">Table of n, a(n) for n = 1..35</a> %e A206956 Some solutions for n=4 %e A206956 ..1..1..1..0..0..1..2....1..2..2..0..1..2..2....0..2..2..1..1..2..2 %e A206956 ..2..0..0..0..2..0..2....2..1..0..1..2..2..2....1..2..0..1..1..2..2 %e A206956 ..2..0..1..1..0..0..2....2..1..1..1..0..2..2....1..0..1..2..0..1..2 %e A206956 ..2..1..2..2..1..2..0....1..2..2..2..2..1..2....2..0..2..2..2..1..2 %K A206956 nonn %O A206956 1,1 %A A206956 _R. H. Hardin_ Feb 13 2012