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 A205758 #7 Jul 22 2025 19:01:13 %S A205758 69338,542718,3797920,34977686,292986186,2917623614,26828234464, %T A205758 279459906314,2723713739666,29190925331248,295846244829092, %U A205758 3230320670138002,33638289242782070,371863257488907590 %N A205758 Number of 7X(n+1) 0..2 arrays with every 2X2 subblock having the same number of equal edges as its horizontal neighbors and a different number from its vertical neighbors, and new values 0..2 introduced in row major order. %C A205758 Row 6 of A205753 %H A205758 R. H. Hardin, <a href="/A205758/b205758.txt">Table of n, a(n) for n = 1..28</a> %e A205758 Some solutions for n=4 %e A205758 ..0..1..0..2..1....0..0..0..0..0....0..1..2..2..2....0..1..0..1..0 %e A205758 ..2..0..1..0..2....0..1..1..1..1....1..1..1..1..2....0..0..0..1..0 %e A205758 ..2..0..0..0..0....2..2..0..2..0....2..0..2..0..2....2..1..2..2..2 %e A205758 ..1..1..2..1..2....0..2..2..2..2....2..0..2..2..2....1..1..1..2..1 %e A205758 ..0..1..1..1..1....1..1..0..1..0....2..1..1..0..1....0..2..0..2..0 %e A205758 ..2..2..0..2..0....1..0..0..0..0....2..1..0..0..0....0..0..0..2..0 %e A205758 ..2..0..0..2..0....2..2..1..2..1....0..1..2..1..2....1..2..1..2..1 %K A205758 nonn %O A205758 1,1 %A A205758 _R. H. Hardin_ Jan 30 2012