A190629 Half the number of n X n symmetric binary matrices with no element equal to a strict majority of its vertical, antidiagonal and horizontal neighbors

1, 1, 3, 15, 115, 1587, 33283, 1147868, 64664807, 5886944926, 868821662115, 207892029761070, 80727613405529244, 50826500691456029359, 51893686154530928512158, 85927150265759233982684320

Offset

1,3

Links

R. H. Hardin, Table of n, a(n) for n = 1..20

Example

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

Crossrefs

Sequence in context: A331122 A342167 A346272 * A341647 A074596 A087806

Adjacent sequences: A190626 A190627 A190628 * A190630 A190631 A190632

Keyword

nonn

Author

R. H. Hardin May 14 2011

Status

approved