%I #11 Sep 15 2023 12:02:46
%S 450,3111,22877,148389,945748,5125790,27587386,130018165,611215024,
%T 2593349603,10992085241,43067682706,168673810979,621760259909,
%U 2291824059768,8059474696068,28348577031630,96115434260034
%N Number of (2+1) X (n+1) 0..2 arrays with every 2 X 2 subblock sum nondecreasing horizontally, vertically and antidiagonally ne-to-sw.
%H R. H. Hardin, <a href="/A253376/b253376.txt">Table of n, a(n) for n = 1..210</a>
%H R. H. Hardin, <a href="/A253376/a253376.txt">Empirical recurrence of order 79</a>
%F Empirical recurrence of order 79 (see link above).
%e Some solutions for n=4
%e ..0..0..1..1..0....0..0..0..0..1....0..0..1..2..1....0..2..0..0..0
%e ..0..0..0..0..2....1..1..2..2..2....1..2..1..1..2....1..0..1..2..2
%e ..2..0..2..1..1....2..0..1..0..2....2..0..2..2..2....1..1..1..0..1
%Y Row 2 of A253375.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 30 2014