A206390 Number of n X n 0..5 arrays with no element equal to another within a city block distance of two, and new values 0..5 introduced in row major order.

1, 1, 26, 1931, 170796, 21983256, 3889732730, 998388746378

Offset

1,3

Comments

Diagonal of A206396.

Links

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

Example

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

Crossrefs

Cf. A206396.

Sequence in context: A054853 A257947 A245929 * A268089 A173949 A266030

Adjacent sequences: A206387 A206388 A206389 * A206391 A206392 A206393

Keyword

nonn

Author

R. H. Hardin Feb 07 2012

Status

approved