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%I #8 May 17 2018 09:11:52
%S 2,104,660,2474,6604,14696,28490,50448,83092,129642,193292,278240,
%T 388258,528328,703140,918330,1179228,1492584,1864202,2301584,2811588,
%U 3402266,4081084,4857344,5738882,6735720,7856884,9112842,10513196,12069800
%N Number of -n..n arrays x(0..3) of 4 elements with zeroth through 3rd differences all nonzero.
%C Row 4 of A199943.
%H R. H. Hardin, <a href="/A199945/b199945.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n) = a(n-1) +2*a(n-2) -3*a(n-4) -3*a(n-5) +3*a(n-6) +3*a(n-7) -2*a(n-9) -a(n-10) +a(n-11).
%F Empirical g.f.: 2*x*(1 + 51*x + 276*x^2 + 803*x^3 + 1408*x^4 + 1731*x^5 + 1436*x^6 + 825*x^7 + 303*x^8 + 78*x^9) / ((1 - x)^5*(1 + x)^2*(1 + x + x^2)^2). - _Colin Barker_, May 17 2018
%e Some solutions for n=6:
%e ..2...-5...-6...-1....4....1...-4...-4...-3....6....1....1...-5....5...-1....4
%e ..1....1...-3...-5....3...-5...-3....5...-6...-6...-2...-5...-3...-1....6...-6
%e .-5....6....1...-2...-6...-4...-5....2....1...-5....5....1...-2...-4...-6...-5
%e ..3....4....3....2...-3....5....2...-5....3...-1....1...-1....3....4...-4...-6
%Y Cf. A199943.
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 12 2011
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