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Number of -3..3 arrays x(0..n-1) of n elements with zero sum, adjacent elements differing by more than one, and elements alternately increasing and decreasing
1

%I #5 Mar 31 2012 12:36:38

%S 1,6,14,48,144,482,1534,5148,16826,56918,188706,642300,2149072,

%T 7348408,24749244,84919630,287439908,988917344,3360535304,11586463472,

%U 39498606276,136421151864,466287543690,1612808711870,5524756100592

%N Number of -3..3 arrays x(0..n-1) of n elements with zero sum, adjacent elements differing by more than one, and elements alternately increasing and decreasing

%C Column 3 of A200192

%H R. H. Hardin, <a href="/A200187/b200187.txt">Table of n, a(n) for n = 1..200</a>

%e Some solutions for n=5

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

%e .-3....3....3....2...-3....2...-2....2...-2...-3...-3....2....2...-3....2...-2

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

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

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

%K nonn

%O 1,2

%A _R. H. Hardin_ Nov 14 2011