A194572 - OEIS

%I #5 Dec 18 2015 18:17:44

%S 1,5,193,80780,225623340,3211386454648,223665935176544829,

%T 76009506543180381646618,126023279808505699474721273930,

%U 1019406708191445081689134021299430885

%N Number of lower triangles of an n X n 0..4 array with new values introduced in row major order 0..4 and no element equal to more than two horizontal or vertical neighbors

%C Column 4 of A194576

%e Some solutions for 3X3

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

%e ..1.2....1.2....1.1....1.2....1.0....1.1....1.2....1.0....0.1....1.2....1.2

%e ..1.3.1..3.2.2..2.2.1..3.2.0..2.0.2..2.1.3..1.0.1..0.1.1..2.1.1..0.1.3..3.1.2

%K nonn

%O 1,2

%A _R. H. Hardin_ Aug 29 2011