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 A206785 #7 May 28 2021 12:26:41 %S A206785 2,4,4,7,16,7,12,49,49,12,20,144,230,144,20,33,400,1020,1020,400,33, %T A206785 54,1089,4120,6752,4120,1089,54,88,2916,16109,39276,39276,16109,2916, %U A206785 88,143,7744,61003,219061,316744,219061,61003,7744,143,232,20449,227197,1165366 %N A206785 T(n,k) = Number of n X k 0..1 arrays avoiding 0 0 1 horizontally and 0 1 1 vertically. %C A206785 Table starts %C A206785 ..2....4......7......12........20.........33..........54...........88 %C A206785 ..4...16.....49.....144.......400.......1089........2916.........7744 %C A206785 ..7...49....230....1020......4120......16109.......61003.......227197 %C A206785 .12..144...1020....6752.....39276.....219061.....1165366......6052170 %C A206785 .20..400...4120...39276....316744....2431277....17515482....122505076 %C A206785 .33.1089..16109..219061...2431277...25571618...248652016...2339185464 %C A206785 .54.2916..61003.1165366..17515482..248652016..3210775788..40009922008 %C A206785 .88.7744.227197.6052170.122505076.2339185464.40009922008.659966594476 %H A206785 R. H. Hardin, <a href="/A206785/b206785.txt">Table of n, a(n) for n = 1..363</a> %e A206785 Some solutions for n=4, k=3 %e A206785 ..0..0..0....0..0..0....0..0..0....1..0..0....1..1..0....1..1..0....0..1..1 %e A206785 ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....1..0..1....1..1..0 %e A206785 ..0..0..0....1..0..1....1..1..1....1..0..1....1..1..1....1..0..0....0..1..1 %e A206785 ..1..1..1....0..0..0....0..0..0....0..1..0....0..0..0....0..1..1....1..0..0 %Y A206785 Column 1 is A000071(n+3). %Y A206785 Column 2 is A188516. %K A206785 nonn,tabl %O A206785 1,1 %A A206785 _R. H. Hardin_ Feb 12 2012