A190656 Half the number of n X n symmetric binary matrices with no element unequal to a strict majority of its king-move neighbors.

1, 1, 1, 2, 5, 20, 86, 486, 3495, 31938, 368832, 5412981, 100924470, 2390092072, 71686035608, 2726514241955, 131508854502755, 8039052200861454, 622678408143680652

Offset

1,4

Links

Table of n, a(n) for n=1..19.

Example

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

Crossrefs

Sequence in context: A170947 A006228 A363140 * A262166 A262167 A262168

Adjacent sequences: A190653 A190654 A190655 * A190657 A190658 A190659

Keyword

nonn

Author

R. H. Hardin, May 16 2011

Status

approved