A220961 Equals two maps: number of 4Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, diagonal and antidiagonal neighbors in a random 0..3 4Xn array

1, 94, 1224, 33708, 627760, 11214779, 190881959

Offset

1,2

Comments

Row 4 of A220959

Links

Table of n, a(n) for n=1..7.

Example

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

Crossrefs

Sequence in context: A093294 A107613 A220797 * A218648 A278321 A189414

Adjacent sequences: A220958 A220959 A220960 * A220962 A220963 A220964

Keyword

nonn

Author

R. H. Hardin Dec 26 2012

Status

approved