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

2, 8, 62, 944, 37012, 3754497, 1009485843, 732609096798

Offset

1,1

Comments

Diagonal of A227165

Links

Table of n, a(n) for n=1..8.

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

Adjacent sequences: A227157 A227158 A227159 * A227161 A227162 A227163

Keyword

nonn

Author

R. H. Hardin Jul 03 2013

Status

approved