A222893 Number of nX4 0..7 arrays with no element equal to another at a city block distance of exactly two, and new values 0..7 introduced in row major order

7, 389, 84521, 46407465, 30122054696, 20029573364121, 13364073847082009, 8921070496957305924

Offset

1,1

Comments

Column 4 of A222894

Links

Table of n, a(n) for n=1..8.

Example

Some solutions for n=3
..0..1..2..3....0..1..1..2....0..1..1..2....0..1..2..2....0..1..2..3
..3..4..4..5....3..3..4..4....3..4..5..5....3..1..4..3....4..1..5..6
..2..2..1..1....1..5..5..1....5..2..6..7....4..2..0..3....7..6..4..2

Crossrefs

Sequence in context: A058275 A184954 A185354 * A009712 A128793 A042527

Adjacent sequences: A222890 A222891 A222892 * A222894 A222895 A222896

Keyword

nonn

Author

R. H. Hardin Mar 08 2013

Status

approved