editing
approved
R. H. Hardin, <a href="/A233846/a233846.txt">Empirical recurrence of order 56</a>
R. H. Hardin, <a href="/A233846/b233846.txt">Table of n, a(n) for n = 1..210</a>
allocated for R. H. Hardin
Number of (1+2)X(n+2) 0..3 arrays with no increasing sequence of length 3 horizontally or antidiagonally downwards
201664, 9828513, 480071296, 23453646656, 1144779904896, 55884483506105, 2727732140106016, 133143607148769360, 6498789675465401792, 317209014468004733569, 15483100618582896359504, 755736565677187286591248
1,1
Row 1 of A233845
Empirical recurrence of order 56 (see link above)
Some solutions for n=1
..1..1..1....0..3..2....0..0..0....0..3..3....0..3..0....1..1..1....1..3..1
..0..2..1....3..3..0....0..2..1....2..2..2....2..3..1....3..3..0....1..1..1
..1..0..0....2..3..2....1..0..1....3..1..2....2..0..1....1..1..1....1..0..1
allocated
nonn
R. H. Hardin, Dec 16 2013