A253321 - OEIS

%I #4 Dec 30 2014 11:46:50

%S 121,373,1217,2538,6190,11795,25659,48085,99653,188562,382854,736066,

%T 1481812,2889153,5795537,11413655,22859675,45310136,90683516,

%U 180442820,361012010,719966855,1440188551,2875847161,5752209057,11494526782

%N Number of (n+1)X(3+1) 0..1 arrays with every 2X2 subblock sum nondecreasing horizontally, vertically and antidiagonally ne-to-sw

%C Column 3 of A253326

%H R. H. Hardin, <a href="/A253321/b253321.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) +2*a(n-2) -26*a(n-3) +16*a(n-4) +62*a(n-5) -70*a(n-6) -62*a(n-7) +109*a(n-8) +14*a(n-9) -76*a(n-10) +16*a(n-11) +20*a(n-12) -8*a(n-13) for n>15

%e Some solutions for n=4

%e ..0..0..0..1....0..0..0..0....0..0..0..1....0..0..0..1....0..0..1..0

%e ..0..0..0..0....0..0..0..0....0..1..0..1....0..1..0..0....0..0..0..0

%e ..0..0..1..0....0..0..0..0....1..0..1..1....0..0..0..1....1..1..1..1

%e ..1..0..1..0....1..0..1..1....1..1..1..1....1..0..1..1....1..1..1..1

%e ..1..1..1..1....1..0..1..1....0..1..1..1....0..1..1..0....1..1..1..1

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 30 2014