A220330 Equals two maps: number of 3Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..1 3Xn array

1, 12, 92, 572, 4062, 29467, 213225, 1540686, 11163495, 80656708, 581473349, 4190483128, 30199355040, 217538559602, 1566825952174, 11283025994195, 81236036737903, 584831754731217, 4210022381269251, 30304818855812080

Offset

1,2

Comments

Row 3 of A220328

Links

R. H. Hardin, Table of n, a(n) for n = 1..22

Example

Some solutions for n=3
..0..1..0....0..0..0....0..0..0....0..1..1....0..1..0....0..1..0....0..0..0
..0..1..0....1..0..1....1..1..0....0..1..0....0..1..1....1..1..0....0..0..1
..0..0..0....1..1..0....0..1..0....1..1..0....0..0..0....0..1..0....0..1..0

Crossrefs

Sequence in context: A298397 A246585 A120990 * A055022 A220937 A221291

Adjacent sequences: A220327 A220328 A220329 * A220331 A220332 A220333

Keyword

nonn

Author

R. H. Hardin Dec 10 2012

Status

approved