cp's OEIS Frontend

A201809 Number of arrays of n integers in -6..6 with sum zero and equal numbers of elements greater than zero and less than zero.

%I A201809 #7 Jul 22 2025 16:21:28
%S A201809 1,13,37,949,4501,99961,637393,12004357,93039589,1554288913,
%T A201809 13794790153,211729119889,2069010499921,29916152015413,
%U A201809 313278539674477,4343800080821797,47825160489621541,643987273822751329
%N A201809 Number of arrays of n integers in -6..6 with sum zero and equal numbers of elements greater than zero and less than zero.
%C A201809 Column 6 of A201811
%H A201809 R. H. Hardin, <a href="/A201809/b201809.txt">Table of n, a(n) for n = 1..210</a>
%e A201809 Some solutions for n=6
%e A201809 ..5....1...-1....0...-1....5...-6....6....2....3....6....3....0....6....2...-4
%e A201809 ..6...-3...-4...-5....2....2...-1...-1...-4....5....1...-6....0...-5...-4....4
%e A201809 .-5....5...-3....4...-4...-2...-4....2...-6....2....3...-5....6....2...-5....1
%e A201809 .-3...-3....6....5...-2...-6....5...-4...-1...-4...-4....4...-6...-3....3...-2
%e A201809 .-6....0....1....0....2....6....1...-4....6...-2...-5...-1...-4....4...-2....4
%e A201809 ..3....0....1...-4....3...-5....5....1....3...-4...-1....5....4...-4....6...-3
%K A201809 nonn
%O A201809 1,2
%A A201809 _R. H. Hardin_ Dec 05 2011