A188240 Number of nondecreasing arrangements of 7 numbers in -(n+5)..(n+5) with sum zero and not more than two numbers equal.

1082, 2395, 4818, 8964, 15696, 26123, 41748, 64370, 96346, 140463, 200176, 279520, 383424, 517461, 688344, 903624, 1172142, 1503785, 1910034, 2403502, 2998722, 3711609, 4560190, 5564140, 6745632, 8128589, 9739838, 11608268, 13765902

Offset: 1

Author

R. H. Hardin Mar 24 2011

Keywords

• nonn

Comments

Row 7 of A188236

Examples

			Some solutions for n=4
.-6...-7...-9...-8...-7...-5...-8...-9...-4...-8...-6...-6...-6...-8...-9...-7
.-4...-5...-9...-6...-6...-5...-5...-8...-3...-7...-6...-5...-6...-8...-5...-7
.-2...-2....1...-3...-2...-1...-5...-8...-3...-3....0...-5...-3...-1...-1...-4
.-1....0....3...-1...-1...-1....0....3...-1...-1....0....1....1...-1....0...-1
..1....3....3....1...-1....1....5....6....2....6....1....2....1....4....2....6
..5....3....5....8....8....5....6....8....3....6....3....5....5....6....6....6
..7....8....6....9....9....6....7....8....6....7....8....8....8....8....7....7
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n)=2*a(n-1)-a(n-3)-a(n-5)+a(n-6)-2*a(n-7)+2*a(n-8)+a(n-9)-a(n-13)-2*a(n-14)+2*a(n-15)-a(n-16)+a(n-17)+a(n-19)-2*a(n-21)+a(n-22)