A230936 Number of white-square subarrays of (n+2) X (n+2) 0..3 arrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, no adjacent elements equal, and upper left element zero.

0, 6, 34, 1242, 28216, 4092246, 318984080, 159130979900, 43562979789278, 76371552378548280, 73355302704339455588

Offset

1,2

Comments

Diagonal of A230940.

Links

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

Example

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

Crossrefs

Cf. A230940.

Sequence in context: A262104 A161323 A003423 * A230941 A359571 A145000

Adjacent sequences: A230933 A230934 A230935 * A230937 A230938 A230939

Keyword

nonn

Author

R. H. Hardin, Nov 01 2013

Status

approved