|
Search: id:A095693
|
|
|
| A095693 |
|
Triangle read by rows: T(n,k)= the number of digraphs with maximum local degree 2 which contain n labeled nodes and k edges. |
|
+0
4
|
|
| 1, 1, 0, 1, 1, 1, 1, 3, 6, 1, 1, 6, 21, 22, 6, 1, 10, 55, 130, 130, 22, 1, 15, 120, 485, 1005, 822, 130, 1, 21, 231, 1400, 4830, 8547, 6202, 822
(list; table; graph; listen)
|
|
|
OFFSET
|
0,8
|
|
|
COMMENT
|
Sum of the each row of the triangle corresponds to sequence A000985. The diagonal of the triangular array T(n,1) represents the triangular numbers (A000217) The T(n,2) diagonal represents the doubly triangular numbers (A002817)
|
|
REFERENCES
|
Horne, Nicholas S. "Analysis of Viable Network Configurations from a Combinatorial, Graphical and Algebraic Perspective." Diss. Providence College, 2004.
|
|
EXAMPLE
|
T(3,2)=6 since there are six ways that a digraph with 3 nodes can be constructed with 2 edges such that no vertex has local degree greater than two.
|
|
CROSSREFS
|
Cf. A000985, A000217, A002817.
Sequence in context: A008953 A104611 A076790 this_sequence A032660 A102257 A091425
Adjacent sequences: A095690 A095691 A095692 this_sequence A095694 A095695 A095696
|
|
KEYWORD
|
nonn,tabl
|
|
AUTHOR
|
Nicholas S. Horne (nickhorne(AT)cox.net), Jul 06 2004
|
|
|
Search completed in 0.002 seconds
|
