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A199895 Number of -5..5 arrays x(0..n-1) of n elements with zero sum, and adjacent elements not both strictly positive and not both strictly negative.

%I A199895 #7 Jul 22 2025 13:26:06
%S A199895 1,11,51,351,2031,13363,82555,536967,3409609,22163661,142744843,
%T A199895 930121865,6040974735,39482258363,257848379869,1690142722447,
%U A199895 11081263427471,72823380368573,478876538926483,3154101346620987
%N A199895 Number of -5..5 arrays x(0..n-1) of n elements with zero sum, and adjacent elements not both strictly positive and not both strictly negative.
%C A199895 Column 5 of A199898
%H A199895 R. H. Hardin, <a href="/A199895/b199895.txt">Table of n, a(n) for n = 1..200</a>
%e A199895 Some solutions for n=6
%e A199895 ..3...-2...-1...-2....0...-3....0...-1....3....4...-2...-2...-2...-5...-3...-2
%e A199895 .-5....2....4....5....4....1...-2....0...-5...-4....3....1....1....0....2....3
%e A199895 ..5...-4...-2...-4...-4...-3....3...-5....1....1...-2...-2...-3....2...-5....0
%e A199895 .-3....4....0....3....1....1...-2....2...-4....0....4....0....3....0....3...-5
%e A199895 ..1...-3....3...-5...-5....0....0....0....0...-1...-4....3....0....5...-1....4
%e A199895 .-1....3...-4....3....4....4....1....4....5....0....1....0....1...-2....4....0
%K A199895 nonn
%O A199895 1,2
%A A199895 _R. H. Hardin_ Nov 11 2011