A227098 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 two, with rows and columns of the latter in lexicographically nondecreasing order

2, 15, 239, 8427, 754758, 180409504

Offset

1,1

Comments

Diagonal of A227103

Links

Table of n, a(n) for n=1..6.

Example

Some solutions for n=4
..0..0..1..1....0..1..0..0....0..0..0..0....0..1..1..0....0..0..1..0
..0..1..0..0....1..0..1..0....0..0..0..1....1..1..0..1....0..0..0..0
..1..1..1..0....1..0..0..1....1..0..1..0....1..1..0..0....1..0..0..1
..1..1..0..0....1..0..0..1....1..0..0..0....0..0..1..1....1..1..0..1

Crossrefs

Sequence in context: A302358 A192561 A356587 * A180610 A156750 A292798

Adjacent sequences: A227095 A227096 A227097 * A227099 A227100 A227101

Keyword

nonn

Author

R. H. Hardin Jul 01 2013

Status

approved