A193480 Number of n X n symmetric 0..1 arrays with each element equal to the product mod 2 of two of its horizontal and vertical neighbors.

0, 2, 4, 26, 240, 4063, 110576, 5046694, 390350577, 51445991632, 11496127271424, 4348804724288989, 2784306483759192151, 3019459887601073667024, 5548682373331641079067391, 17274304412990968236505863156

Offset

1,2

Links

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

Example

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

Crossrefs

Sequence in context: A019034 A091759 A262067 * A032076 A182146 A218077

Adjacent sequences: A193477 A193478 A193479 * A193481 A193482 A193483

Keyword

nonn

Author

R. H. Hardin, Jul 27 2011

Status

approved