login
A227084
Number of n X n binary arrays indicating whether each 2X2 subblock of a larger binary array has lexicographically increasing rows and columns, for some larger (n+1)X(n+1) binary array with rows and columns of the latter in lexicographically nondecreasing order
0
2, 12, 99, 1339, 34862, 2016091, 272856711, 87559140736
OFFSET
1,1
COMMENTS
Diagonal of A227089
EXAMPLE
Some solutions for n=4
..0..1..1..0....0..1..1..0....0..0..0..0....0..1..0..0....0..0..0..0
..1..1..0..0....1..1..0..1....0..0..0..1....1..1..0..0....0..1..1..0
..1..0..0..0....1..0..0..0....0..0..1..1....0..0..1..1....0..0..0..0
..0..1..0..1....0..0..1..1....0..0..0..0....1..0..1..0....0..0..0..1
CROSSREFS
Sequence in context: A012548 A012550 A009816 * A064370 A138421 A224403
KEYWORD
nonn
AUTHOR
R. H. Hardin Jun 30 2013
STATUS
approved