A181206 T(n,k) = number of n X k matrices containing a permutation of 1..n*k moving each element at most to a neighboring position.

1, 2, 2, 3, 9, 3, 5, 32, 32, 5, 8, 121, 229, 121, 8, 13, 450, 1845, 1845, 450, 13, 21, 1681, 14320, 32000, 14320, 1681, 21, 34, 6272, 112485, 535229, 535229, 112485, 6272, 34, 55, 23409, 880163, 9049169, 19114420, 9049169, 880163, 23409, 55, 89, 87362

Offset

1,2

Comments

Also, the number of perfect matchings in the graph P_2 X P_k X P_n. - Andrew Howroyd, May 17 2017

Links

Alois P. Heinz, Table of n, a(n) for n = 1..210 (first 180 terms from R. H. Hardin)

Example

Table starts:
..1......2.........3............5................8..................13
..2......9........32..........121..............450................1681
..3.....32.......229.........1845............14320..............112485
..5....121......1845........32000...........535229.............9049169
..8....450.....14320.......535229.........19114420...........692276437
.13...1681....112485......9049169........692276437.........53786626921
.21...6272....880163....152526845......24972353440.......4161756233501
.34..23409...6895792...2573281769.....901990734650.....322462050747008
.55..87362..54003765..43402320448...32567565264292...24976513162427653
.89.326041.422983905.732106008249.1176040842289105.1934824269280528177
...
All solutions for 3X2
..1..2....1..2....1..2....1..2....1..2....1..2....1..2....1..2....1..2....1..4
..3..4....4..3....4..3....4..6....3..4....3..6....5..4....5..3....5..6....3..2
..5..6....5..6....6..5....3..5....6..5....5..4....3..6....6..4....3..4....5..6
...
..1..4....1..4....2..1....2..1....2..1....2..1....2..1....2..1....2..1....2..1
..3..2....5..2....4..3....4..3....4..6....3..4....3..4....3..6....5..4....5..3
..6..5....3..6....5..6....6..5....3..5....5..6....6..5....5..4....3..6....6..4
...
..2..1....2..4....2..4....2..4....3..1....3..1....3..1....3..2....3..2....3..2
..5..6....1..3....1..3....1..6....4..2....4..2....5..2....1..4....1..4....1..6
..3..4....5..6....6..5....3..5....5..6....6..5....6..4....5..6....6..5....5..4
...
..3..4....3..4
..1..2....1..2
..5..6....6..5

Crossrefs

Columns k=1-10 give: A000045(n+1), A006253, A028447, A028448, A028449, A028450, A028451, A287052, A287053, A287054.

Main diagonal gives A181205.

Sequence in context: A241475 A132812 A203371 * A274959 A143307 A278463

Adjacent sequences: A181203 A181204 A181205 * A181207 A181208 A181209

Keyword

nonn,tabl

Author

R. H. Hardin, Oct 10 2010

Status

approved