A209366 Number of n X n 1..3 arrays with no element with value z exactly a city block distance of z from another element with value z

3, 39, 115, 968, 19434, 677448, 43249360, 5008603698, 1040887695040, 390290619582728, 263701318486632444, 321337793316358945352, 705783458367197689313992

Offset

1,1

Comments

Diagonal of A209374

Links

Table of n, a(n) for n=1..13.

Example

Some solutions for n=5
..3..1..2..1..3....2..2..3..1..2....2..2..3..1..3....1..3..1..2..2
..1..3..1..3..2....1..3..1..3..2....1..3..1..3..1....2..1..3..1..3
..2..2..3..1..3....3..1..2..1..3....3..1..2..2..3....2..3..1..3..1
..1..3..1..2..1....1..3..1..3..1....1..3..1..3..1....3..1..3..1..3
..3..1..3..2..3....2..2..3..1..2....3..1..3..1..3....1..2..2..3..1

Crossrefs

Sequence in context: A134106 A153875 A082954 * A292542 A212664 A342969

Adjacent sequences: A209363 A209364 A209365 * A209367 A209368 A209369

Keyword

nonn

Author

R. H. Hardin Mar 07 2012

Status

approved