A220532 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..3 nXk array

1, 1, 1, 2, 6, 2, 4, 27, 27, 4, 7, 107, 274, 107, 7, 12, 461, 2660, 2660, 461, 12, 21, 1844, 23948, 53150, 23948, 1844, 21, 37, 7502, 204634, 947486, 947486, 204634, 7502, 37, 65, 29893, 1697940, 15864668, 32675630, 15864668, 1697940, 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.....2660....23948...204634...1697940.13869434

..4...107....2660....53150...947486.15864668.258344332

..7...461...23948...947486.32675630

.12..1844..204634.15864668

.21..7502.1697940

.37.29893

.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..1..1....0..0..0..0....1..1..0..0....0..1..1..1
..0..0..0..1....0..1..1..1....1..0..0..0....1..1..1..0....0..0..0..1
..0..0..0..0....1..1..1..1....0..1..1..0....1..1..0..0....1..0..1..1

Crossrefs

Column 1 is A005251(n+1)

Sequence in context: A220430 A220279 A221188 * A060295 A102912 A064850

Adjacent sequences: A220529 A220530 A220531 * A220533 A220534 A220535

Keyword

nonn,tabl

Author

R. H. Hardin Dec 15 2012

Status

approved