|
| |
|
|
A000184
|
|
Number of genus 0 rooted maps with 3 faces with n vertices
(Formerly M2128 N0843)
|
|
1
| |
|
|
2, 22, 164, 1030, 5868, 31388, 160648, 795846, 3845020, 18211380, 84876152, 390331292, 1775032504, 7995075960, 35715205136, 158401506118, 698102372988, 3059470021316, 13341467466520, 57918065919924, 250419305769512, 1078769490401032, 4631680461623664, 19825379450255900, 84622558822506328, 360270317908904328, 1530148541536781488, 6484511936352543096, 27423786092731382000, 115756362341775227888
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 2,1
|
|
|
REFERENCES
| N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
Tutte, W. T.; On the enumeration of planar maps. Bull. Amer. Math. Soc. 74 1968 64-74.
T. R. S. Walsh, Combinatorial Enumeration of Non-Planar Maps. Ph.D. Dissertation, Univ. of Toronto, 1971.
T. R. S. Walsh and A. B. Lehman, Counting rooted maps by genus, J. Comb. Thy B13 (1972), 122-141 and 192-218.
|
|
|
LINKS
| Richard P. Stanley, CATALAN ADDENDUM, version of Jul 19, 2008, p. 24. [From Jonathan Vos Post (jvospost3(AT)gmail.com), Aug 16 2008]
|
|
|
FORMULA
| Appears to be 2 * A029887(n). - R. Stephan, Aug 17 2004
a(n) = 4^n*GAMMA(n+3/2)/(3*sqrt(Pi)*GAMMA(n)) - n*4^(n-1) [From Mark van Hoeij (hoeij(AT)math.fsu.edu), Jul 06 2010]
|
|
|
CROSSREFS
| Sequence in context: A202738 A123960 A091169 * A007613 A043037 A058441
Adjacent sequences: A000181 A000182 A000183 * A000185 A000186 A000187
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
|
|
|
EXTENSIONS
| More terms from Sean A. Irvine (sairvin(AT)xtra.co.nz), Nov 14 2010
|
| |
|
|
