A186931 Number of (n+1) X (n+1) binary arrays with every 2 X 2 subblock trace equal to exactly one or two horizontal and vertical neighbor 2 X 2 subblock traces.

0, 104, 1840, 59720, 3026432, 264604776, 35582947920, 8132915749352, 2989994168957168

Offset

1,2

Comments

Diagonal of A186939.

Links

Table of n, a(n) for n=1..9.

Example

Some solutions for 4 X 4
..1..1..1..1....1..0..0..0....0..0..1..0....0..1..0..1....1..0..1..0
..1..1..0..0....1..0..0..1....1..0..0..0....0..0..0..1....1..0..1..1
..1..1..0..0....1..0..0..1....1..0..0..1....1..0..0..0....1..1..1..1
..1..1..0..0....0..0..0..1....1..0..0..1....0..0..1..1....1..1..0..1

Crossrefs

Cf. A186939.

Sequence in context: A223420 A250325 A244946 * A273224 A092714 A297977

Adjacent sequences: A186928 A186929 A186930 * A186932 A186933 A186934

Keyword

nonn

Author

R. H. Hardin Mar 01 2011

Status

approved