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
Keywords
Examples
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
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
Comments