|
| |
|
|
A054362
|
|
Number of unlabeled 4-gonal cacti having n polygons.
|
|
0
| |
|
|
1, 1, 1, 3, 11, 52, 307, 1936, 13207, 93496, 683988, 5127163, 39230669, 305299420, 2410624122, 19273255184, 155780437711, 1271253542364, 10462650241996, 86765190816362, 724450039738076, 6086167189623746, 51416796881915019
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,4
|
|
|
LINKS
| Miklos Bona, Michel Bousquet, Gilbert Labelle, 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 := 4: 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: A179322 A014510 A058799 * A129833 A107958 A053557
Adjacent sequences: A054359 A054360 A054361 * A054363 A054364 A054365
|
|
|
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
|
| |
|
|
