A183903 Number of nondecreasing arrangements of n+3 numbers in 0..8 with each number being the sum mod 9 of three others.

1, 9, 242, 1866, 6503, 15973, 33236, 62678, 110487, 185231, 298538, 465912, 707702, 1050242, 1527181, 2181023, 3064898, 4244586, 5800817, 7831871, 10456503

Offset: 1

Author

R. H. Hardin Jan 07 2011

Keywords

• nonn

Comments

Column 8 of A183904

Examples

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

Formula

Empirical: a(n) = (1/40320)*n^8 + (1/672)*n^7 + (37/960)*n^6 + (9/16)*n^5 + (9709/1920)*n^4 + (917/32)*n^3 + (14159/10080)*n^2 - (119065/168)*n + 801 for n>5