A188227 - OEIS

%I #6 Mar 31 2012 12:36:11

%S 1,3,12,81,598,4859,41748,374820,3475284,33053399,320869264,

%T 3167899567,31721907390,321494911644,3292220700520,34018798556265,

%U 354312456839426,3716173628641396,39220841304052510,416264662788000213

%N Number of nondecreasing arrangements of n numbers in -(2n-2)..(2n-2) with sum zero and not more than two numbers equal

%C Diagonal of A188236

%H R. H. Hardin, <a href="/A188227/b188227.txt">Table of n, a(n) for n = 1..22</a>

%e Some solutions for n=4

%e .-1...-3...-3...-3...-4...-5...-6...-5...-4...-5...-3...-3...-2...-6...-2...-4

%e .-1....0...-2...-1...-1...-2...-1....0....1...-1...-1...-3...-2...-4...-1...-4

%e ..1....1....0....1...-1....1....2....2....1....2....2....3....2....4....0....2

%e ..1....2....5....3....6....6....5....3....2....4....2....3....2....6....3....6

%K nonn

%O 1,2

%A _R. H. Hardin_ Mar 24 2011