%I #5 Mar 31 2012 12:36:38
%S 2064,26932,352840,4664818,62361448,838749476,11349503058,
%T 154248783948,2104280597600,28798650135574,395207143815892,
%U 5436349736878032,74936087200093134,1034832015199700638,14313834216014729042
%N Number of -7..7 arrays x(0..n+2) of n+3 elements with zero sum and nonzero second and third differences
%C Column 7 of A200204
%H R. H. Hardin, <a href="/A200203/b200203.txt">Table of n, a(n) for n = 1..31</a>
%e Some solutions for n=3
%e ..1....0...-7....1....0...-7....1....0....1...-7....5...-7....0....0...-7...-4
%e .-7...-1....0...-4....6....5....1....5....7...-3....0....1...-4....7...-1...-7
%e ..4...-1...-1....2...-5...-2....6....3...-5....5....2....2....5....1...-3....7
%e .-2...-2....4....2....1....7...-7...-3....0....4...-7....7...-3...-2....4....3
%e ..6....3....7...-6....3...-2...-4...-2...-4....6....1...-7....5...-7....2....6
%e .-2....1...-3....5...-5...-1....3...-3....1...-5...-1....4...-3....1....5...-5
%K nonn
%O 1,1
%A _R. H. Hardin_ Nov 14 2011