Location via proxy:   [ UP ]  
[Report a bug]   [Manage cookies]                
A227160
Number of n X n 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X(n+1) binary array having a sum of one or less, with rows and columns of the latter in lexicographically nondecreasing order
0
2, 8, 62, 944, 37012, 3754497, 1009485843, 732609096798
OFFSET
1,1
COMMENTS
Diagonal of A227165
EXAMPLE
Some solutions for n=4
..1..1..1..0....1..1..0..0....1..1..0..0....1..1..0..0....1..0..0..0
..1..1..0..0....1..0..0..0....1..0..0..1....1..0..0..0....0..1..1..1
..0..0..1..1....1..0..1..1....0..0..1..1....0..0..0..1....0..1..1..1
..0..0..0..1....0..1..1..0....0..1..1..1....0..1..0..0....0..0..1..0
CROSSREFS
Sequence in context: A230824 A006245 A202751 * A191604 A009271 A153539
KEYWORD
nonn
AUTHOR
R. H. Hardin Jul 03 2013
STATUS
approved