A221188 T(n,k)=Equals two maps: number of nXk binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, vertical and antidiagonal neighbors in a random 0..2 nXk array

1, 1, 1, 2, 6, 2, 4, 27, 27, 4, 7, 107, 274, 107, 7, 12, 461, 2648, 2648, 461, 12, 21, 1844, 23765, 51924, 23765, 1844, 21, 37, 7502, 203122, 928133, 928133, 203122, 7502, 37, 65, 29893, 1686374, 15638551, 32233374, 15638551, 1686374, 29893, 65, 114, 119342

Offset

1,4

Comments

Table starts

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

..1.....6......27......107......461.....1844......7502....29893.119342

..2....27.....274.....2648....23765...203122...1686374.13787513

..4...107....2648....51924...928133.15638551.256020803

..7...461...23765...928133.32233374

.12..1844..203122.15638551

.21..7502.1686374

.37.29893

.65

Links

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

Example

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

Crossrefs

Column 1 is A005251(n+1)

Column 2 is A220529

Sequence in context: A220375 A220430 A220279 * A220532 A060295 A102912

Adjacent sequences: A221185 A221186 A221187 * A221189 A221190 A221191

Keyword

nonn,tabl

Author

R. H. Hardin Jan 04 2013

Status

approved