A265860 Number of nX2 arrays containing 2 copies of 0..n-1 with no element plus any vertical neighbor equal to n-1.

1, 2, 22, 384, 19080, 1019328, 106546608, 11075595648, 1892644922880, 321721729436160, 81376293539485440, 20506177206967265280

Offset

1,2

Comments

Column 2 of A265863.

Links

Table of n, a(n) for n=1..12.

Example

Some solutions for n=4
..0..3....3..2....3..0....1..3....1..2....2..1....3..1....1..2....0..1....3..2
..0..3....3..2....1..0....1..2....0..0....2..3....2..1....3..2....1..0....1..0
..1..2....1..0....3..2....3..0....2..1....0..1....0..3....3..0....3..2....1..0
..1..2....0..1....1..2....2..0....3..3....0..3....0..2....1..0....2..3....3..2

Crossrefs

Cf. A265863.

Sequence in context: A078232 A151615 A111985 * A138463 A007842 A287595

Adjacent sequences: A265857 A265858 A265859 * A265861 A265862 A265863

Keyword

nonn

Author

R. H. Hardin, Dec 17 2015

Status

approved