A175564 Number of n X n binary matrices that contain no 2 X 2 submatrix consisting of all zeros or all ones.

1, 2, 14, 156, 840, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset

0,2

Links

Table of n, a(n) for n=0..102.

Formula

For n >= 5, a(n) = 0.

Crossrefs

Cf. A175563.

Sequence in context: A301931 A060193 A222200 * A355114 A332693 A196791

Adjacent sequences: A175561 A175562 A175563 * A175565 A175566 A175567

Keyword

easy,nonn

Author

Max Alekseyev, Jul 03 2010

Status

approved