A209180 Number of n X 2 1..6 arrays with no element with value z exactly a city block distance of z from another element with value z.

35, 1104, 31185, 782336, 17015665, 311027162, 5208624406, 85171286099

Offset

1,1

Comments

Column 2 of A209182.

Links

Table of n, a(n) for n=1..8.

Example

Some solutions for n=6
..3..5....4..4....6..3....6..6....2..6....5..6....6..4....3..1....5..1....3..3
..4..1....6..4....5..3....1..4....5..5....6..4....2..6....2..3....2..3....5..6
..5..5....4..6....1..6....2..6....5..5....4..5....4..6....4..6....4..6....1..2
..2..4....1..5....6..4....6..1....5..4....2..6....6..4....5..1....4..3....4..4
..6..5....2..5....4..1....1..5....2..3....5..3....6..6....3..5....3..6....4..3
..3..3....6..1....6..2....4..2....2..6....3..2....4..2....6..5....1..3....3..6

Crossrefs

Cf. A209182.

Sequence in context: A049395 A278723 A215296 * A115492 A187538 A306685

Adjacent sequences: A209177 A209178 A209179 * A209181 A209182 A209183

Keyword

nonn

Author

R. H. Hardin, Mar 05 2012

Status

approved