A188116 - OEIS

%I #9 Mar 31 2012 12:36:10

%S 0,3,4,16,42,137,426,1398,4622,15594,53252,184060,642392,2261829,

%T 8024726,28664946,103015222,372234190,1351655526,4930080182,

%U 18055480464,66371559466,244817099870,905883648170,3361795172242,12509691344838

%N Number of strictly increasing arrangements of n nonzero numbers in -(n+1)..(n+1) with sum zero

%C Column 3 of A188122

%H R. H. Hardin, <a href="/A188116/b188116.txt">Table of n, a(n) for n = 1..30</a>

%e Some solutions for n=6

%e .-4...-5...-7...-7...-7...-5...-7...-7...-7...-7...-6...-7...-5...-5...-7...-6

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

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

%e ..2...-1....3....2....2....3....2....3....3....2....2....3...-1....1....2....1

%e ..3....5....5....5....4....4....3....4....4....4....6....5....4....3....5....5

%e ..4....6....6....7....5....5....4....6....5....7....7....7....7....4....7....6

%Y Equals A188114(n+2)

%K nonn

%O 1,2

%A _R. H. Hardin_ Mar 21 2011