A184687 1/3 the number of n X n 0..2 arrays with no element equal both to the element above and to the element to its left

1, 24, 4080, 4890528, 41325395328, 2461751303097216, 1033802803683039013248, 3060537246479645213149335744, 63873994081842807211176279381955968, 9397599222467284962086636818784583099209472

Offset

1,2

Comments

Diagonal of A184694

Links

R. H. Hardin, Table of n, a(n) for n = 1..11

Example

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

Crossrefs

Sequence in context: A166768 A326120 A159399 * A007241 A106207 A100089

Adjacent sequences: A184684 A184685 A184686 * A184688 A184689 A184690

Keyword

nonn

Author

R. H. Hardin Jan 20 2011

Status

approved