|
Search: id:A086364
|
|
|
| A086364 |
|
Triangle read by rows: S_D(n,k) = `Type D' Stirling numbers of the second kind. |
|
+0
3
|
|
| 1, 2, 2, 2, 9, 4, 2, 27, 36, 10, 2, 65, 195, 140, 26, 2, 143, 840, 1180, 540, 76, 2, 301, 3171, 7735, 6510, 2142, 232, 2, 619, 11060, 43659, 59920, 34692, 8624, 764, 2, 1257, 36707, 223566, 467691, 423612, 180852, 35856, 2620, 2, 2535, 117960, 1071350
(list; table; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
FORMULA
|
A partition of {-n, ..., -1, 1, ..., n} into nonempty subsets X_1, ..., X_r is called `symmetric' if for each i -X_i = X_j for some j. S_D(n, k) is the number of such symmetric partitions whose induced partition on {1, ..., n} involves k nonempty subsets, and none of the X_i are of the form {j, -j}.
|
|
CROSSREFS
|
Cf. A085483, A086365 (row sums).
Sequence in context: A138056 A022459 A060804 this_sequence A091185 A125695 A138674
Adjacent sequences: A086361 A086362 A086363 this_sequence A086365 A086366 A086367
|
|
KEYWORD
|
easy,nonn,tabl
|
|
AUTHOR
|
James East (jameseastseq(AT)hotmail.com), Sep 04 2003
|
|
|
Search completed in 0.002 seconds
|
