|
Search: id:A000305
|
|
|
| A000305 |
|
Number of certain rooted planar maps.
(Formerly M3543 N1435)
|
|
+0
3
|
|
| 1, 4, 18, 89, 466, 2537, 14209, 81316, 473338, 2793454, 16674417, 100487896, 610549829, 3735850007, 23000055178, 142370597601, 885521350882, 5531501612071, 34686798239678, 218273864005214, 1377897874711437
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
REFERENCES
|
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
W. G. Brown, Enumeration of non-separable planar maps, Canad. J. Math., 15 (1963), 526-545.
|
|
MAPLE
|
with(linalg): T := proc(n, k) if k<=n then k*sum((2*j-k+1)*(j-1)!*(3*n-k-j)!/(j-k+1)!/(j-k)!/(2*k-j-1)!/(n-j)!, j=k..min(n, 2*k-1))/(2*n-k+1)! else 0 fi end:A := matrix(30, 30, T): seq(sum(A[i, j], j=1..i), i=1..30);
|
|
CROSSREFS
|
Row sums of A046652.
Sequence in context: A127394 A046984 A129323 this_sequence A020070 A036749 A011270
Adjacent sequences: A000302 A000303 A000304 this_sequence A000306 A000307 A000308
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
N. J. A. Sloane (njas(AT)research.att.com).
|
|
EXTENSIONS
|
More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 03 2004
|
|
|
Search completed in 0.002 seconds
|
