A274722 Number of n X n 0..2 arrays with no element equal to any value at offset (-1,-2), (-2,-1) or (-1,0) and new values introduced in order 0..2.

1, 6, 68, 1632, 84948, 8960464, 1980677448, 905233056800, 860544738080372, 1705630286322728068

Offset

1,2

Comments

Diagonal of A274728.

Links

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

Example

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

Crossrefs

Cf. A274728.

Sequence in context: A355219 A014505 A363396 * A347927 A127184 A333795

Adjacent sequences: A274719 A274720 A274721 * A274723 A274724 A274725

Keyword

nonn

Author

R. H. Hardin, Jul 03 2016

Status

approved