A222833 Number of n X n 0..3 arrays with no element equal to another at a city block distance of exactly two, and new values 0..3 introduced in row major order

1, 7, 72, 600, 4032, 24576, 138240, 743424, 3833856, 19267584, 94371840, 454557696

Offset

1,2

Comments

Diagonal of A222838

Links

Table of n, a(n) for n=1..12.

Example

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

Crossrefs

Sequence in context: A093632 A242827 A077332 * A005413 A306377 A230890

Adjacent sequences: A222830 A222831 A222832 * A222834 A222835 A222836

Keyword

nonn

Author

R. H. Hardin Mar 06 2013

Status

approved