A266035 - OEIS

%I #4 Dec 20 2015 07:46:37

%S 1,55,481,5594,121029,2045306,33026298,562735444,9532097947,

%T 160132082576,2699812308573,45545430005680,767636583946670,

%U 12939677383177473,218153972376875945,3677676423588950515,61997693315879549117

%N Number of 3Xn integer arrays with each element equal to the number of horizontal and antidiagonal neighbors less than itself.

%C Row 3 of A266033.

%H R. H. Hardin, <a href="/A266035/b266035.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=4

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

%e ..2..0..4..1....1..3..4..0....2..1..0..2....0..0..0..1....0..1..4..0

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

%Y Cf. A266033.

%K nonn

%O 1,2

%A _R. H. Hardin_, Dec 20 2015