A221292 Equals two maps: number of 4Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..3 4Xn array

1, 37, 556, 9107, 172904, 2890017, 49684593, 821323042, 13475380990

Offset

1,2

Comments

Row 4 of A221290

Links

Table of n, a(n) for n=1..9.

Example

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

Crossrefs

Sequence in context: A219440 A219141 A220938 * A231514 A156226 A217501

Adjacent sequences: A221289 A221290 A221291 * A221293 A221294 A221295

Keyword

nonn

Author

R. H. Hardin Jan 09 2013

Status

approved