A194618 - OEIS

A194618

Half the number of lower triangles of a 5 X 5 0..n array with no element equal to the average of its horizontal and vertical neighbors.

%I #11 Jun 03 2025 18:36:22

%S 849,571364,86867366,3703163910,73569838704,873084601728,

%T 7416076339907,47683223919057,251059904306865,1116910109397146,

%U 4348691274427714,15090969268080476,47709109611064061,138700124724207796

%N Half the number of lower triangles of a 5 X 5 0..n array with no element equal to the average of its horizontal and vertical neighbors.

%H R. H. Hardin, <a href="/A194618/b194618.txt">Table of n, a(n) for n = 1..18</a>

%e Some solutions for n=2

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

%e ..2.0........2.0........2.0........1.0........2.0........1.0........2.0

%e ..2.0.2......0.2.0......0.1.0......1.0.1......0.2.1......1.0.2......0.1.0

%e ..2.2.0.1....1.2.2.0....1.1.0.1....0.1.1.2....0.1.2.0....1.0.0.0....2.2.2.0

%e ..1.1.1.1.2..2.2.1.0.1..0.0.2.1.2..0.1.1.0.1..2.2.0.2.0..0.1.0.2.0..0.2.0.0.2

%Y Row 4 of A194615.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 30 2011