Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #5 Mar 31 2012 12:36:11
%S 1,5,18,69,252,920,3370,12346,45207,165821,609734,2247151,8300708,
%T 30734578,114067100,424306230,1581788460,5909243454,22120325320,
%U 82963636468,311732564498,1173377033602,4424032482238,16706682557212
%N Number of strictly increasing arrangements of n numbers in -(n+3)..(n+3) with sum zero
%C Column 5 of A188181
%H R. H. Hardin, <a href="/A188177/b188177.txt">Table of n, a(n) for n = 1..28</a>
%e Some solutions for n=6
%e .-8...-8...-9...-8...-9...-8...-9...-6...-9...-8...-4...-9...-4...-9...-8...-8
%e .-4...-7...-1...-3...-2...-7...-3...-2...-3...-7...-3...-8...-3...-6...-5...-3
%e .-3...-1....0...-2....0...-4...-2...-1...-1...-3...-2....0...-2....1...-3...-1
%e .-1....4....1....0....1....2....2....0....3....2....2....3...-1....3....0....0
%e ..7....5....3....5....2....8....5....1....4....7....3....6....3....5....7....5
%e ..9....7....6....8....8....9....7....8....6....9....4....8....7....6....9....7
%K nonn
%O 1,2
%A _R. H. Hardin_ Mar 23 2011