A203174 Number of n X n 0..2 arrays with every 1 immediately preceded by 0 to the left or above, no 0 immediately preceded by a 0, and every 2 immediately preceded by 0 1 to the left or above.

1, 1, 7, 59, 952, 32411, 2208945, 323885934, 84492757788, 47354744651060, 53683376052551785, 116641756206417848067, 528882406558326590368278

Offset: 1

Author

R. H. Hardin Dec 30 2011

Keywords

• nonn

Comments

Diagonal of A203181

Examples

			Some solutions for n=5
..0..1..0..1..2....0..1..0..1..2....0..1..0..1..2....0..1..2..0..1
..1..0..1..2..0....1..0..1..0..1....1..0..1..0..1....1..0..1..2..0
..0..1..0..1..1....2..1..2..1..0....2..1..2..1..0....0..1..2..0..1
..1..0..1..0..2....0..2..0..1..1....0..1..0..2..1....1..0..1..1..0
..0..1..0..1..2....1..0..1..0..2....1..0..1..2..2....0..1..0..1..2