|
%I #4 Jan 11 2015 10:03:06
%S 450,2723,10182,29737,70590,148134,298760,587522,1126853,2134789,
%T 4034824,7609993,14320586,26934197,50677637,95365268,179465371,
%U 337787639,635898370,1197229227,2254216671,4244626838,7992870420,15051425511
%N Number of (2+1)X(n+1) 0..2 arrays with every 2X2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically
%C Row 2 of A253749
%H R. H. Hardin, <a href="/A253750/b253750.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 5*a(n-1) -10*a(n-2) +12*a(n-3) -9*a(n-4) -5*a(n-5) +25*a(n-6) -35*a(n-7) +33*a(n-8) -15*a(n-9) -15*a(n-10) +33*a(n-11) -35*a(n-12) +25*a(n-13) -5*a(n-14) -9*a(n-15) +12*a(n-16) -10*a(n-17) +5*a(n-18) -a(n-19) for n>25
%e Some solutions for n=4
%e ..2..0..0..2..2....2..0..0..0..2....1..1..1..1..2....0..0..0..1..2
%e ..1..1..2..1..0....2..1..0..1..1....1..1..1..2..2....2..2..2..1..2
%e ..1..2..1..0..2....2..1..1..1..2....1..1..2..2..2....1..1..0..1..2
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 11 2015
| 