A190655 Half the number of n X n symmetric binary matrices with no element unequal to a strict majority of its diagonal and antidiagonal neighbors.

1, 2, 4, 24, 224, 2862, 53010, 1527552, 65195940, 4097065492, 385902826186, 54089022594864, 11269850153217786, 3491854976674289164, 1609153719436211880868, 1102542409006001885651456

Offset

1,2

Links

R. H. Hardin, Table of n, a(n) for n = 1..18

Example

Some solutions for n=5 with a(1,1)=0
..0..1..1..0..1....0..1..0..0..1....0..1..0..1..1....0..1..0..0..1
..1..0..0..1..1....1..0..1..1..0....1..0..1..1..0....1..0..1..1..0
..1..0..0..1..0....0..1..1..0..0....0..1..1..0..0....0..1..0..0..1
..0..1..1..0..0....0..1..0..0..1....1..1..0..0..1....0..1..0..0..0
..1..1..0..0..0....1..0..0..1..0....1..0..0..1..0....1..0..1..0..0

Crossrefs

Sequence in context: A032107 A378581 A141307 * A038049 A382205 A151817

Adjacent sequences: A190652 A190653 A190654 * A190656 A190657 A190658

Keyword

nonn

Author

R. H. Hardin, May 16 2011

Status

approved