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A175564 Number of n X n binary matrices that contain no 2 X 2 submatrix consisting of all zeros or all ones. 1
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 (list; graph; refs; listen; history; text; internal format)
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 * A196791 A218295 A268011

Adjacent sequences:  A175561 A175562 A175563 * A175565 A175566 A175567

KEYWORD

easy,nonn

AUTHOR

Max Alekseyev, Jul 03 2010

STATUS

approved

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Last modified December 15 15:01 EST 2019. Contains 329999 sequences. (Running on oeis4.)