Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #4 Jan 05 2015 22:17:29
%S 8664,131378,1955619,29206325,438592379,6586610559,98874441146,
%T 1484785130392,22297719051563,334849977802421,5028613048594528,
%U 75517616024925219,1134092007833070215,17031337435362085847
%N Number of (2+2)X(n+2) 0..2 arrays with every consecutive three elements in every row and diagonal having one or two distinct values, and in every column and antidiagonal having two or three distinct values, and new values 0 upwards introduced in row major order
%C Row 2 of A253615
%H R. H. Hardin, <a href="/A253617/b253617.txt">Table of n, a(n) for n = 1..210</a>
%e Some solutions for n=2
%e ..0..0..0..1....0..0..1..1....0..0..0..1....0..0..0..0....0..0..1..1
%e ..1..1..0..0....1..2..1..2....1..0..1..1....1..1..2..1....2..2..0..0
%e ..2..1..1..1....0..2..0..0....2..2..0..0....0..1..1..0....0..2..2..1
%e ..0..2..2..0....0..0..1..0....0..2..2..1....1..2..2..0....2..1..1..0
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 05 2015