A188336 Number of nondecreasing arrangements of 6 nonzero numbers in -(n+4)..(n+4) with sum zero

197, 424, 828, 1488, 2519, 4050, 6252, 9314, 13479, 19008, 26224, 35472, 47169, 61756, 79754, 101712, 128267, 160088, 197940, 242622, 295041, 356138, 426970, 508634, 602351, 709384, 831128, 969024, 1124655, 1299652, 1495796, 1714918

Offset

1,1

Comments

Row 6 of A188333

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)+2*a(n-8)-a(n-11)-a(n-13)+2*a(n-15)-a(n-16).

Empirical: G.f. -x*(-197 -30*x +20*x^2 -29*x^3 +33*x^4 -37*x^5 -64*x^6 -157*x^7 +5*x^8 +27*x^9 +84*x^10 +24*x^11 +67*x^12 -46*x^13 -130*x^14 +78*x^15) / ( (1+x+x^2) *(x^4+x^3+x^2+x+1) *(x^2+1) *(1+x)^2 *(x-1)^6 ). - R. J. Mathar, Mar 28 2011

Example

Some solutions for n=6
-10..-10...-3...-9...-7...-9...-9...-6...-7...-5...-7...-4...-6...-5...-9...-9
.-4...-6...-2...-3...-6...-1...-9...-6...-5...-4...-3...-3...-2...-5...-8...-7
..1...-1...-2...-1...-2...-1...-4....1...-5...-4...-1...-1...-2...-2...-2....2
..2....5....1...-1....1...-1....4....1....4....2....2....2....3...-2....4....3
..4....5....3....4....4....6....9....4....5....4....4....3....3....6....5....4
..7....7....3...10...10....6....9....6....8....7....5....3....4....8...10....7

Crossrefs

Sequence in context: A158223 A142503 A142568 * A142230 A142414 A142812

Adjacent sequences: A188333 A188334 A188335 * A188337 A188338 A188339

Keyword

nonn

Author

R. H. Hardin Mar 28 2011

Status

approved