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 A209045 #7 Jul 22 2025 21:36:13 %S A209045 972,1503212,2364812680,3724317998214,5866193355938718, %T A209045 9239962457023110368,14554067523333615991960, %U A209045 22924432479225632829691864,36108778942762030367945973348,56875733727363424301468394080962 %N A209045 Number of nX6 0..3 arrays with no element equal the average of immediate neighbors vertically above and horizontally left of it. %C A209045 Column 6 of A209047 %H A209045 R. H. Hardin, <a href="/A209045/b209045.txt">Table of n, a(n) for n = 1..210</a> %e A209045 Some solutions for n=4 %e A209045 ..0..1..0..3..2..3....2..0..1..2..0..2....2..3..1..0..1..3....0..3..0..1..0..3 %e A209045 ..1..2..2..1..3..2....3..0..1..3..2..0....0..0..1..1..2..3....3..0..2..1..0..1 %e A209045 ..0..3..3..0..1..3....0..1..0..1..0..1....3..3..3..0..0..2....0..1..1..0..3..3 %e A209045 ..2..1..1..2..1..1....3..3..3..3..3..0....1..1..3..1..0..0....1..2..3..3..0..3 %K A209045 nonn %O A209045 1,1 %A A209045 _R. H. Hardin_ Mar 04 2012