|
| |
|
|
A054365
|
|
Number of unlabeled 5-gonal cacti having n polygons.
|
|
0
| |
|
|
1, 1, 1, 3, 17, 102, 811, 6626, 58385, 532251, 5011934, 48344880, 475982471, 4766639628, 48434621610, 498363430232, 5184274255789, 54451326151253, 576810990484823, 6156943228387305, 66170786572330174, 715564777086617766
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,4
|
|
|
LINKS
| Miklos Bona, Michel Bousquet, Gilbert Labelle and Pierre Leroux, Enumeration of m-ary cacti, Advances in Applied Mathematics, 24 (2000), 22-56 (pdf, dvi).
Index entries for sequences related to cacti
|
|
|
MAPLE
| with(combinat): with(numtheory): m := 5: for p from 2 to 28 do s1 := 0: s2 := 0: for d from 1 to p do if p mod d = 0 then s1 := s1+phi(p/d)*binomial(m*d, d) fi: od: for d from 1 to p-1 do if gcd(m, p-1) mod d = 0 then s2 := s2+phi(d)*binomial((p*m)/d, (p-1)/d) fi: od: printf(`%d, `, (s1+s2)/(m*p)-binomial(m*p, p)/(p*(m-1)+1)) od:
|
|
|
CROSSREFS
| Sequence in context: A161473 A161940 A074565 * A116886 A163064 A020069
Adjacent sequences: A054362 A054363 A054364 * A054366 A054367 A054368
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Simon Plouffe (simon.plouffe(AT)gmail.com)
|
|
|
EXTENSIONS
| More terms and Maple program from Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Dec 01 2006
|
| |
|
|
