A185409 T(n,k)=1/7 the number of nXk 0..6 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

0, 1, 1, 1, 13, 1, 7, 150, 150, 7, 13, 1848, 5040, 1848, 13, 55, 22656, 279918, 279918, 22656, 55, 133, 278832, 12205368, 53808534, 12205368, 278832, 133, 463, 3430776, 595974240, 9560464068, 9560464068, 595974240, 3430776, 463, 1261, 42221928

Offset

1,5

Comments

Table starts

....0........1...........1.............7............13............55

....1.......13.........150..........1848.........22656........278832

....1......150........5040........279918......12205368.....595974240

....7.....1848......279918......53808534....9560464068.1755419411964

...13....22656....12205368....9560464068.6409594156632

...55...278832...595974240.1755419411964

..133..3430776.27536905674

..463.42221928

.1261

Links

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

Example

Some solutions for 4X3 with a(1,1)=0
..0..3..6....0..0..0....0..0..4....0..0..3....0..3..6....0..3..3....0..0..0
..0..3..6....4..4..4....0..4..4....3..3..3....0..3..6....0..2..2....4..4..4
..2..4..4....1..5..4....0..5..5....3..2..2....5..0..6....1..1..1....5..5..6
..2..2..2....1..5..5....4..4..4....1..1..1....5..0..6....6..6..6....0..0..6

Crossrefs

Column 1 is A015441(n-1)

Sequence in context: A111738 A389368 A202134 * A010235 A393305 A196381

Adjacent sequences: A185406 A185407 A185408 * A185410 A185411 A185412

Keyword

nonn,tabl

Author

R. H. Hardin, Jan 26 2011

Status

approved