A185560 1/4 the number of n X n 0..3 arrays with no element equal both to the element above and to the element to its left

1, 60, 50580, 598507920, 99407416968000, 231753101877188629380, 7583858300260627032845531520, 3483475434832751291309593655505225600, 22459143127863154464679826472043109609252549520

Offset

1,2

Comments

Diagonal of A185567

Links

R. H. Hardin, Table of n, a(n) for n = 1..10

Example

Some solutions for 3X3 with a(1,1)=0
..0..1..2....0..3..2....0..0..0....0..3..2....0..2..1....0..0..0....0..0..3
..3..1..1....1..2..0....1..2..2....0..0..0....1..3..0....0..2..0....3..3..0
..3..3..1....1..2..0....3..3..3....1..1..3....0..1..3....0..0..2....0..0..1

Crossrefs

Sequence in context: A092870 A221936 A225990 * A003788 A222019 A123378

Adjacent sequences: A185557 A185558 A185559 * A185561 A185562 A185563

Keyword

nonn

Author

R. H. Hardin Jan 31 2011

Status

approved