%I #6 Dec 18 2015 18:17:44
%S 5,35,557,19379,1481501,248381815,91397735301,73818960495633,
%T 130889487125186283,509545270244514585603,4355460540545035980173055,
%U 81748120032524783307283152379,3369206664229541719414619846139771
%N Number of lower triangles of an n X n 0..4 array with no element differing from any of its horizontal or vertical neighbors by more than one
%C Column 4 of A194931
%H R. H. Hardin, <a href="/A194927/b194927.txt">Table of n, a(n) for n = 1..15</a>
%e Some solutions for 4X4
%e ..3........1........1........3........2........3........3........4
%e ..3.2......2.3......2.2......3.2......2.1......2.1......3.3......3.4
%e ..2.1.2....2.3.3....3.3.2....4.3.3....1.1.2....3.2.1....4.4.3....2.3.2
%e ..2.2.1.2..3.2.3.4..2.2.2.3..4.3.3.3..2.2.3.2..2.1.2.2..4.3.4.3..1.2.1.2
%K nonn
%O 1,1
%A _R. H. Hardin_ Sep 05 2011