A220329 Equals two maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..1 2Xn array

1, 4, 16, 48, 174, 658, 2482, 9229, 33982, 125217, 461351, 1699127, 6252129, 22995280, 84546207, 310785413, 1142206689, 4197260747, 15421867303, 56659522539, 208152496049, 764662949438, 2808941077111, 10318186228202

Offset

1,2

Comments

Row 2 of A220328

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Example

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

Crossrefs

Sequence in context: A215723 A034918 A119003 * A222387 A366608 A222936

Adjacent sequences: A220326 A220327 A220328 * A220330 A220331 A220332

Keyword

nonn

Author

R. H. Hardin Dec 10 2012

Status

approved