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A200061 Number of -n..n arrays x(0..6) of 7 elements with zero sum and elements alternately strictly increasing and strictly decreasing 1

%I

%S 14,472,4224,20978,74338,211242,514168,1115572,2215290,4099888,

%T 7165376,11941380,19119208,29580842,44432366,65037696,93057524,

%U 130487666,179703518,243503094,325156994,428455996,557766736,718083722,915090720

%N Number of -n..n arrays x(0..6) of 7 elements with zero sum and elements alternately strictly increasing and strictly decreasing

%C Row 7 of A200057

%H R. H. Hardin, <a href="/A200061/b200061.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = 2*a(n-1) -a(n-3) -a(n-5) +a(n-6) -2*a(n-7) +2*a(n-8) +a(n-9) -a(n-13) -2*a(n-14) +2*a(n-15) -a(n-16) +a(n-17) +a(n-19) -2*a(n-21) +a(n-22)

%e Some solutions for n=6

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

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Nov 13 2011

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Last modified October 19 03:10 EDT 2021. Contains 348073 sequences. (Running on oeis4.)