A251491 - OEIS

%I #4 Dec 03 2014 10:11:41

%S 236,3456,3456,50576,186304,50576,740096,10046784,10046784,740096,

%T 10830016,541815424,1996407424,541815424,10830016,158478336,

%U 29219848960,396684056960,396684056960,29219848960,158478336,2319053056

%N T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with no 2X2 subblock having the sum of its diagonal elements less than the minimum of its antidiagonal elements

%C Table starts

%C ......236........3456..........50576.............740096..............10830016

%C .....3456......186304.......10046784..........541815424...........29219848960

%C ....50576....10046784.....1996407424.......396684056960........78819515764397

%C ...740096...541815424...396684056960....290403118046224....212595602301764864

%C .10830016.29219848960.78819515764397.212595602301764864.573419887491673696912

%H R. H. Hardin, <a href="/A251491/b251491.txt">Table of n, a(n) for n = 1..144</a>

%F Empirical for column k:

%F k=1: a(n) = 16*a(n-1) -20*a(n-2)

%F k=2: [order 7]

%F k=3: [order 16]

%F k=4: [order 48]

%e Some solutions for n=2 k=4

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

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

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

%K nonn,tabl

%O 1,1

%A _R. H. Hardin_, Dec 03 2014