A221629 Number of 7Xn arrays with each row a permutation of 1..n having at least as many downsteps as the preceding row

1, 8, 29124, 183919920, 15258126049410, 2638115823321645192, 2031241364747667201263520, 3210318128660193294063849550080, 13896214616394139128043246845049514250

Offset

1,2

Comments

Row 7 of A221623

Links

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

Example

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

Crossrefs

Sequence in context: A281359 A067070 A115478 * A362280 A013788 A156178

Adjacent sequences: A221626 A221627 A221628 * A221630 A221631 A221632

Keyword

nonn

Author

R. H. Hardin Jan 21 2013

Status

approved