A199896 - OEIS

%I #5 Mar 31 2012 12:36:37

%S 1,13,67,545,3573,27457,193689,1462859,10651367,80142549,593254327,

%T 4466635929,33386730231,251884546233,1894568061637,14327147198653,

%U 108231414777793,820328179730055,6216861991058925,47216885967426099

%N Number of -6..6 arrays x(0..n-1) of n elements with zero sum, and adjacent elements not both strictly positive and not both strictly negative

%C Column 6 of A199898

%H R. H. Hardin, <a href="/A199896/b199896.txt">Table of n, a(n) for n = 1..200</a>

%e Some solutions for n=6

%e .-5....3....5...-3...-2....2....2....2...-5....2....0....0...-6....0...-1...-2

%e ..2....0...-4....2....3....0...-5...-3....5...-2....1...-3....5...-2....3....2

%e .-2....4....2....0....0....2....5....2...-3....3...-5....6....0....3...-6...-3

%e ..6...-4...-5....0...-1...-2...-4...-4....0...-6....5...-2...-2...-1....3....0

%e ..0....0....4....6....1....2....6....4...-1....6...-1....3....0....6...-4....3

%e .-1...-3...-2...-5...-1...-4...-4...-1....4...-3....0...-4....3...-6....5....0

%K nonn

%O 1,2

%A _R. H. Hardin_ Nov 11 2011