cp's OEIS Frontend

A200056 Number of -7..7 arrays x(0..n-1) of n elements with zero sum and elements alternately strictly increasing and strictly decreasing.

%I A200056 #7 Jul 22 2025 15:39:42
%S A200056 1,14,106,850,7074,59910,514168,4453946,38855488,341052122,3006680636,
%T A200056 26619825378,236386648574,2105717447626,18798362729604,
%U A200056 168222072625668,1507848061916274,13541292792666004,121763260320351938
%N A200056 Number of -7..7 arrays x(0..n-1) of n elements with zero sum and elements alternately strictly increasing and strictly decreasing.
%C A200056 Column 7 of A200057
%H A200056 R. H. Hardin, <a href="/A200056/b200056.txt">Table of n, a(n) for n = 1..189</a>
%e A200056 Some solutions for n=6
%e A200056 ..1....3....1...-6...-5....4...-1....2...-1...-5....6...-3....0...-6....6....1
%e A200056 ..5...-4....3....4...-6....5....4...-4....2....6...-1...-1...-4....7...-3....2
%e A200056 .-2...-1....2...-6....4...-5...-5...-1...-3...-4....1...-5....7...-7....7...-3
%e A200056 ..7...-5....5....1...-1....0....0...-2....3....4...-7....5...-5....0...-3....5
%e A200056 .-7....6...-7....0....6...-3...-3....5...-4...-7....4....0....5...-1....0...-7
%e A200056 .-4....1...-4....7....2...-1....5....0....3....6...-3....4...-3....7...-7....2
%K A200056 nonn
%O A200056 1,2
%A A200056 _R. H. Hardin_ Nov 13 2011