A232949 Number of n X n 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, diagonally or antidiagonally, and top left element zero

1, 21, 1881, 685251, 1074244299, 7168373617095, 205030957086979647, 25121788915317351455997, 13201474923932116066095060171, 29758989052767328125373420316820645

Offset

1,2

Comments

Diagonal of A232955

Links

R. H. Hardin, Table of n, a(n) for n = 1..11

Example

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

Crossrefs

Sequence in context: A203327 A297652 A243664 * A305145 A296686 A163928

Adjacent sequences: A232946 A232947 A232948 * A232950 A232951 A232952

Keyword

nonn

Author

R. H. Hardin, Dec 02 2013

Status

approved