A192325 Half the number of n X n symmetric binary matrices with no element both equal to all its immediate N and W neighbors if they exist and unequal to all its immediate E and S neighbors if they exist

1, 0, 2, 16, 244, 6938, 371342, 37280140, 7016898676, 2476338996046, 1638683680332022, 2033288154472125378, 4730646433644468299754, 20637618504497727985203276, 168817037972490215464239418020

Offset

1,3

Links

R. H. Hardin, Table of n, a(n) for n = 1..21

Example

Some solutions for 4X4 with a(1,1)=0
..0..0..0..1....0..0..0..0....0..0..0..0....0..0..1..0....0..0..1..0
..0..1..0..1....0..1..1..0....0..1..0..0....0..0..0..0....0..0..0..1
..0..0..1..0....0..1..0..1....0..0..1..0....1..0..1..0....1..0..0..0
..1..1..0..1....0..0..1..0....0..0..0..1....0..0..0..1....0..1..0..1

Crossrefs

Sequence in context: A217813 A217814 A217815 * A009233 A188560 A012462

Adjacent sequences: A192322 A192323 A192324 * A192326 A192327 A192328

Keyword

nonn

Author

R. H. Hardin Jun 28 2011

Status

approved