A220375 T(n,k)=Equals two maps: number of nXk binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and vertical neighbors in a random 0..2 nXk array.

1, 1, 1, 2, 6, 2, 4, 23, 23, 4, 7, 94, 236, 94, 7, 12, 380, 2095, 2095, 380, 12, 21, 1494, 18296, 39780, 18296, 1494, 21, 37, 5939, 154562, 722126, 722126, 154562, 5939, 37, 65, 23398, 1280878, 12480964, 26483660, 12480964, 1280878, 23398, 65, 114, 92317

Offset

1,4

Comments

Table starts

..1.....1.......2........4........7.......12........21.......37....65.114

..1.....6......23.......94......380.....1494......5939....23398.92317

..2....23.....236.....2095....18296...154562...1280878.10492879

..4....94....2095....39780...722126.12480964.209958887

..7...380...18296...722126.26483660

.12..1494..154562.12480964

.21..5939.1280878

.37.23398

.65

Links

R. H. Hardin, Table of n, a(n) for n = 1..49

Example

Some solutions for n=3 k=4
..1..0..1..1....0..0..0..0....0..0..0..0....1..1..0..1....0..0..0..0
..1..1..0..1....0..1..0..0....1..1..1..1....1..1..0..1....0..1..0..1
..0..0..1..0....0..0..0..1....1..1..1..1....0..1..1..1....0..0..1..1

Crossrefs

Column 1 is A005251(n+1)

Sequence in context: A385859 A085193 A220242 * A220430 A220279 A221188

Adjacent sequences: A220372 A220373 A220374 * A220376 A220377 A220378

Keyword

nonn,tabl

Author

R. H. Hardin, Dec 13 2012

Status

approved