A221438 T(n,k) is the number of n X k 1..(max n,k) arrays with each row and column having unrepeated values.

1, 2, 2, 6, 2, 6, 24, 12, 12, 24, 120, 216, 12, 216, 120, 720, 5280, 576, 576, 5280, 720, 5040, 190800, 66240, 576, 66240, 190800, 5040, 40320, 9344160, 15321600, 161280, 161280, 15321600, 9344160, 40320, 362880, 598066560, 5411750400, 283046400

Offset: 1

Author

R. H. Hardin, Jan 16 2013

Keywords

• nonn
• tabl

Comments

Table starts:

....1.......2..........6...........24............120............720

....2.......2.........12..........216...........5280.........190800

....6......12.........12..........576..........66240.......15321600

...24.....216........576..........576.........161280......283046400

..120....5280......66240.......161280.........161280......812851200

..720..190800...15321600....283046400......812851200......812851200

.5040.9344160.5411750400.782137036800.20449013760000.61479419904000

Examples

			Some solutions for n=3 and k=4:
..4..1..3..2....3..1..4..2....1..2..4..3....3..4..2..1....2..3..4..1
..2..3..4..1....1..3..2..4....3..4..1..2....1..2..3..4....1..4..3..2
..1..4..2..3....2..4..3..1....2..1..3..4....2..1..4..3....3..2..1..4
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..83

Crossrefs

Diagonal is A002860.

Column 1 is A000142.

Column 2 is A082491.