A251802 - OEIS

%I #4 Dec 09 2014 07:39:55

%S 1740,28932,348679,3352272,27291608,195753488,1271711747,7634258216,

%T 42987423526,229660644080,1174599406053,5792185593840,27697451048182,

%U 129039115827548,587993778478925,2629056738236432,11566062999511464

%N Number of (2+1)X(n+1) 0..3 arrays with no 2X2 subblock having x11-x00 less than x10-x01

%C Row 2 of A251801

%H R. H. Hardin, <a href="/A251802/b251802.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 40*a(n-1) -755*a(n-2) +8946*a(n-3) -74677*a(n-4) +467156*a(n-5) -2274363*a(n-6) +8833486*a(n-7) -27833039*a(n-8) +71958408*a(n-9) -153781873*a(n-10) +272810702*a(n-11) -402324879*a(n-12) +492639700*a(n-13) -498877265*a(n-14) +414825042*a(n-15) -280100140*a(n-16) +151065320*a(n-17) -63500432*a(n-18) +20037984*a(n-19) -4463424*a(n-20) +625536*a(n-21) -41472*a(n-22)

%e Some solutions for n=2

%e ..3..3..2....1..1..0....2..3..2....0..3..0....2..1..2....0..3..3....2..2..1

%e ..0..1..3....0..1..3....0..0..3....0..0..3....2..3..2....0..0..3....1..1..3

%e ..0..0..0....0..2..0....0..1..0....1..1..1....1..0..2....0..1..3....0..1..1

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 09 2014