A204302 - OEIS

%I #5 Mar 31 2012 12:37:01

%S 256,51680,47834122,59151473070,211637634795580

%N Number of (n+1)X(n+1) 0..3 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards

%C Diagonal of A204309

%e Some solutions for n=4

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 14 2012