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%I #9 May 17 2018 17:02:06
%S 11,23,42,68,103,149,206,276,361,461,578,714,869,1045,1244,1466,1713,
%T 1987,2288,2618,2979,3371,3796,4256,4751,5283,5854,6464,7115,7809,
%U 8546,9328,10157,11033,11958,12934,13961,15041,16176,17366,18613,19919,21284
%N Number of -n..n arrays x(0..3) of 4 elements with zero sum and no element more than one greater than the previous.
%C Row 4 of A199847.
%H R. H. Hardin, <a href="/A199848/b199848.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n) = 3*a(n-1) -3*a(n-2) +2*a(n-3) -3*a(n-4) +3*a(n-5) -a(n-6).
%F Empirical g.f.: x*(11 - 10*x + 6*x^2 - 11*x^3 + 12*x^4 - 4*x^5) / ((1 - x)^4*(1 + x + x^2)). - _Colin Barker_, May 16 2018
%e Some solutions for n=6:
%e ..3....2....4....5....4....1....6....6....5....6....3....1....5....2....3....3
%e ..1....1....2...-1....5....2....2....3...-1....1....1....2....1....1....2....3
%e .-2....2...-1...-2...-5....2...-2...-3...-1...-1....1....1...-3....1...-2...-3
%e .-2...-5...-5...-2...-4...-5...-6...-6...-3...-6...-5...-4...-3...-4...-3...-3
%Y Cf. A199847.
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 11 2011
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