|
Search: id:A069730
|
|
|
| A069730 |
|
Number of nonisomorphic unrooted unicursal planar maps with n edges. |
|
+0
1
|
|
| 1, 2, 4, 13, 50, 248, 1407, 8600, 55154, 365292, 2473956, 17053468, 119191992, 842688120, 6015275094, 43292026736, 313788095994, 2288506113056, 16781638172458, 123656774440396, 915123392599456
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
COMMENT
|
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.
Adjacent sequences: A069727 A069728 A069729 this_sequence A069731 A069732 A069733
Sequence in context: A007858 A005164 A058134 this_sequence A072605 A030953 A030811
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Valery A. Liskovets (liskov(AT)im.bas-net.by), Apr 07 2002
|
|
|
Search completed in 0.002 seconds
|
