A221081 Number of n X n arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor.

0, 4, 270, 279841, 2714713664, 310569670802169, 376959882525471479946, 5114167130942310710200312969

Offset

1,2

Comments

Diagonal of A221087.

Links

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

Example

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

Crossrefs

Cf. A221087.

Sequence in context: A119008 A357559 A108134 * A340916 A000320 A101758

Adjacent sequences: A221078 A221079 A221080 * A221082 A221083 A221084

Keyword

nonn

Author

R. H. Hardin Jan 01 2013

Status

approved