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 A203979 #7 Jul 22 2025 17:42:26 %S A203979 96,864,7776,69984,629856,5668704,51018336,459165024,4132485216, %T A203979 37192366944,334731302496,3012581722464,27113235502176, %U A203979 244019119519584,2196172075676256,19765548681086304,177889938129776736 %N A203979 Number of (n+1)X4 0..2 arrays with no 2X2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..2 introduced in row major order. %C A203979 Column 3 of A203984 %H A203979 R. H. Hardin, <a href="/A203979/b203979.txt">Table of n, a(n) for n = 1..210</a> %F A203979 Empirical: a(n) = 96*9^(n-1) %e A203979 Some solutions for n=4 %e A203979 ..0..0..0..0....0..1..2..2....0..0..1..2....0..1..0..2....0..1..0..0 %e A203979 ..1..2..2..1....2..1..0..0....2..2..1..0....2..2..0..1....2..2..2..1 %e A203979 ..1..0..0..0....2..1..2..1....0..0..1..0....1..1..0..1....0..0..0..0 %e A203979 ..1..2..2..1....0..0..2..0....2..2..2..2....2..2..2..1....1..1..1..1 %e A203979 ..0..0..0..0....1..1..1..0....0..0..1..1....0..0..0..0....2..2..2..2 %K A203979 nonn %O A203979 1,1 %A A203979 _R. H. Hardin_ Jan 09 2012