|
| |
|
|
A066991
|
|
Square array read by antidiagonals of number of ways of dividing nk labeled items into k unlabeled orders with n items in each order.
|
|
0
| |
|
|
1, 1, 2, 1, 12, 6, 1, 120, 360, 24, 1, 1680, 60480, 20160, 120, 1, 30240, 19958400, 79833600, 1814400, 720, 1, 665280, 10897286400, 871782912000, 217945728000, 239500800, 5040, 1, 17297280, 8892185702400, 20274183401472000
(list; table; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,3
|
|
|
COMMENTS
| T(p,k)=(pk)!/k! is divisible by p^k but not p^(k+1) for p prime; e.g. T(3,4)=3^4*11*10*8*7*5*4*2*1=19958400.
|
|
|
FORMULA
| T(n, k)=(nk)!/k!
|
|
|
EXAMPLE
| Rows start: 1,1,1,1,...; 2,12,120,1680,...; 6,360,60480,19958400,...; 24,20160,79833600,871782912000,...
|
|
|
CROSSREFS
| Rows include A000012, A001813, A064350. Columns include A000142, A002674, A065961. Cf. A060538, A060539, A060540.
Sequence in context: A049055 A008285 A119274 * A132875 A050139 A010255
Adjacent sequences: A066988 A066989 A066990 * A066992 A066993 A066994
|
|
|
KEYWORD
| nonn,tabl
|
|
|
AUTHOR
| Henry Bottomley (se16(AT)btinternet.com), Feb 01 2002
|
| |
|
|
