Statements (37)
| Predicate | Object |
|---|---|
| gptkbp:instanceOf |
integer sequence
|
| gptkbp:author |
gptkb:N._J._A._Sloane
|
| gptkbp:citation |
gptkb:A000081
A000088 A000014 |
| gptkbp:describes |
Counts the number of unlabeled trees with n nodes.
|
| gptkbp:field |
combinatorics
|
| gptkbp:first_terms |
2
1 11 23 3 47 6 106 1301 235 551 3159 19320 48629 123867 7741 |
| gptkbp:form |
a(n) = (1/n) * sum_{k=1 to n} P(n, k) * a(k), where P(n, k) is the number of ways to partition n labeled nodes into k nonempty unlabeled trees.
|
| gptkbp:hasKeyword |
easy
nice nonn |
| https://www.w3.org/2000/01/rdf-schema#label |
A000055
|
| gptkbp:OEIS |
gptkb:A000055
https://oeis.org/A000055 |
| gptkbp:relatedConcept |
graph theory
unlabeled trees |
| gptkbp:sequence |
integer sequence
Number of trees with n unlabeled nodes |
| gptkbp:status |
approved
|
| gptkbp:bfsParent |
gptkb:OEIS_A006125
|
| gptkbp:bfsLayer |
7
|