|
| |
|
|
A032181
|
|
Number of ways to partition n labeled elements into pie slices each of at least 2 elements.
|
|
0
| |
|
|
0, 1, 1, 4, 11, 56, 267, 1730, 11643, 93532, 804563, 7789838, 81109107, 923080328, 11250876171, 147433014058, 2056359699659, 30514968348500, 479058943716579, 7942752339181286, 138576460230586755, 2539126631897727808, 48733588613803358939
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,4
|
|
|
LINKS
| C. G. Bower, Transforms (2)
Index entries for sequences related to necklaces
Vladimir Kruchinin, Compositae and their properties , arXiv:1103.2582
|
|
|
FORMULA
| "CIJ" (necklace, indistinct, labeled) transform of 0, 1, 1, 1...
E.g.f.: A(x) = ln(1/(2+x-exp(x))).
a(n) = n! * sum(k=1..n, sum(j=0..k, binomial(k,j) *stirling2(n-k+j,j) *j!/(n-k+j)! *(-1)^(k-j))/k). - From Vladimir Kruchinin (kru(AT)ie.tusur.ru), Feb 01 2011
|
|
|
CROSSREFS
| Sequence in context: A149317 A027042 A051770 * A203577 A081073 A002831
Adjacent sequences: A032178 A032179 A032180 * A032182 A032183 A032184
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Christian G. Bower (bowerc(AT)usa.net)
|
| |
|
|
