A222556 Number of (n+2)X1 arrays of occupancy after each element moves up to +-n places but not 0.

2, 20, 102, 427, 1668, 6372, 24230, 92279, 352596

Offset: 1

Author

R. H. Hardin Feb 24 2013

Keywords

• nonn

Comments

Row 2 of A222555

Examples

			Some solutions for n=3
..1....3....0....0....2....0....0....2....1....2....0....0....3....2....1....1
..3....0....0....1....0....2....0....1....1....1....1....3....0....0....0....0
..0....1....3....0....2....1....4....1....1....0....2....0....0....3....4....3
..0....1....1....1....1....1....0....1....2....1....0....1....2....0....0....0
..1....0....1....3....0....1....1....0....0....1....2....1....0....0....0....1