|
| |
|
|
A069730
|
|
Number of nonisomorphic unrooted unicursal planar maps with n edges.
|
|
0
| |
|
|
1, 2, 4, 13, 50, 248, 1407, 8600, 55154, 365292, 2473956, 17053468, 119191992, 842688120, 6015275094, 43292026736, 313788095994, 2288506113056, 16781638172458, 123656774440396, 915123392599456
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| Unicursal (in a broad sense) means that no more than two vertices are of odd valency (that is maps possessing an Eulerian path).
|
|
|
REFERENCES
| V. A. Liskovets and T. R. S. Walsh, Enumeration of Eulerian and unicursal planar maps, Discr. Math., 282 (2004), 209-221.
|
|
|
FORMULA
| a(n)=A069727(n)+A069724(n)
|
|
|
CROSSREFS
| Cf. A069727, A069724.
Sequence in context: A184177 A005164 A058134 * A072605 A030953 A030811
Adjacent sequences: A069727 A069728 A069729 * A069731 A069732 A069733
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| Valery A. Liskovets (liskov(AT)im.bas-net.by), Apr 07 2002
|
| |
|
|
