cp's OEIS Frontend

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

%I A200061 #7 Jul 22 2025 15:39:57
%S A200061 14,472,4224,20978,74338,211242,514168,1115572,2215290,4099888,
%T A200061 7165376,11941380,19119208,29580842,44432366,65037696,93057524,
%U A200061 130487666,179703518,243503094,325156994,428455996,557766736,718083722,915090720
%N A200061 Number of -n..n arrays x(0..6) of 7 elements with zero sum and elements alternately strictly increasing and strictly decreasing.
%C A200061 Row 7 of A200057
%H A200061 R. H. Hardin, <a href="/A200061/b200061.txt">Table of n, a(n) for n = 1..200</a>
%F A200061 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 A200061 Some solutions for n=6
%e A200061 ..1....4....3...-2....3....6...-3....0...-6...-6...-3....0....4....0...-4....4
%e A200061 .-6....2...-1....0...-6...-6....2....2....6...-4....0...-1....3....4...-6...-6
%e A200061 ..6....4....3...-3....2...-2...-4...-4...-4...-5...-6....0....5...-4....6....5
%e A200061 .-6...-6...-1....0...-3...-3....6....6....4....5....5...-3...-6....3....1...-4
%e A200061 ..3....0....0...-1....4....6...-5...-5....0....3...-3....5...-4...-6....6....4
%e A200061 ..0...-5...-4....6...-6...-3....5....6....1....5....5...-2...-6....4...-4...-5
%e A200061 ..2....1....0....0....6....2...-1...-5...-1....2....2....1....4...-1....1....2
%K A200061 nonn
%O A200061 1,1
%A A200061 _R. H. Hardin_ Nov 13 2011