|
Search: id:A006470
|
|
|
| A006470 |
|
Number of rooted planar maps.
(Formerly M2075)
|
|
+0
3
|
|
| 2, 15, 60, 175, 420, 882, 1680, 2970, 4950, 7865, 12012, 17745, 25480, 35700, 48960, 65892, 87210, 113715, 146300, 185955, 233772, 290950, 358800, 438750, 532350, 641277, 767340, 912485, 1078800, 1268520
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
REFERENCES
|
Walsh, T. R. S.; Lehman, A. B.; Counting rooted maps by genus. III: Nonseparable maps. J. Combinatorial Theory Ser. B 18 (1975), 222-259.
|
|
FORMULA
|
(n+1)*binomial(n+3, 4).
C(n+2, 2)*C(n+4, 3)/2; g.f.: (2+3x)/(1-x)^6. - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Dec 14 2005
|
|
MAPLE
|
a:=n->sum(sum(n^3-n^2, j=0..k)/12, k=0..n): seq(a(n), n=2..31); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 02 2007
a:=n->(sum((numbcomp(n, 5)), j=4..n)):seq(a(n), n=5..34); [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Aug 26 2008]
|
|
CROSSREFS
|
A027789/2.
Sequence in context: A034571 A126019 A071237 this_sequence A084169 A000181 A047146
Adjacent sequences: A006467 A006468 A006469 this_sequence A006471 A006472 A006473
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
njas
|
|
|
Search completed in 0.002 seconds
|
