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%I #4 Mar 31 2012 12:36:38
%S 1,5,13,41,103,275,685,2525,5221,13897,32717,176145,321963,1390895,
%T 2223445,3845743,10539177,76756525,147653093,808935605,934179307
%N Number of 0..4 arrays x(0..n-1) of n elements with zero n-1st difference
%C Column 4 of A200154
%e Some solutions for n=6
%e ..1....1....4....1....2....1....2....4....2....1....1....0....2....1....4....3
%e ..2....0....1....1....1....2....1....0....1....4....1....2....3....4....1....2
%e ..2....2....2....4....3....3....1....2....1....1....3....1....4....3....1....3
%e ..2....4....2....4....3....4....1....4....2....0....4....1....3....2....2....2
%e ..2....4....1....1....1....4....1....4....3....2....3....2....1....2....3....0
%e ..1....1....4....1....2....1....2....4....2....1....1....0....2....1....4....3
%K nonn
%O 1,2
%A _R. H. Hardin_ Nov 13 2011