A200764 Number of 0..n arrays x(0..3) of 4 elements with nondecreasing average value

5, 19, 51, 113, 219, 388, 638, 995, 1483, 2133, 2975, 4047, 5383, 7028, 9022, 11415, 14253, 17593, 21485, 25993, 31173, 37094, 43818, 51421, 59969, 69545, 80221, 92085, 105215, 119706, 135640, 153119, 172231, 193083, 215769, 240403, 267083, 295930

Offset

1,1

Comments

Row 4 of A200763

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 2*a(n-1) +a(n-2) -3*a(n-3) -a(n-4) +a(n-5) +3*a(n-6) -a(n-7) -2*a(n-8) +a(n-9).

Empirical g.f.: -x*(5+9*x+8*x^2+7*x^3+4*x^4+4*x^5-x^6-2*x^7+x^8) / ( (1+x+x^2)*(1+x)^2*(x-1)^5 ). - R. J. Mathar, Nov 22 2011

Example

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

Crossrefs

Sequence in context: A328191 A100104 A015650 * A285987 A055365 A209817

Adjacent sequences: A200761 A200762 A200763 * A200765 A200766 A200767

Keyword

nonn

Author

R. H. Hardin Nov 22 2011

Status

approved