|
Search: id:A003446
|
|
|
| A003446 |
|
Triangulated (n+2)-gons rooted at one of the triangles.
(Formerly M1616)
|
|
+0
1
|
|
| 0, 1, 1, 2, 6, 16, 52, 170, 579, 1996, 7021, 24892, 89214, 321994, 1170282, 4277352, 15715249, 57999700, 214939846, 799478680, 2983699498, 11169391168, 41929537871, 157807451672, 595340479694, 2250901216266, 8527700012092, 32369067177176
(list; graph; listen)
|
|
|
OFFSET
|
0,4
|
|
|
REFERENCES
|
S. J. Cyvin, J. Brunvoll, E. Brendsdal, B. N. Cyvin and E. K. Lloyd, Enumeration of polyene hydrocarbons: a complete mathematical solution, J. Chem. Inf. Comput. Sci., 35 (1995) 743-751
F. Harary, E. M. Palmer and R. C. Read, On the cell-growth problem for arbitrary polygons, Discr. Math. 11 (1975), 371-389.
P. Lisonek, Closed forms for the number of polygon dissections. Journal of Symbolic Computation 20 (1995), 595-601.
R. C. Read, On general dissections of a polygon, Aequat. Math. 18 (1978), 370-388.
P. K. Stockmeyer, The charm bracelet problem and its applications, pp. 339-349 of Graphs and Combinatorics (Washington, Jun 1973), Ed. by R. A. Bari and F. Harary. Lect. Notes Math., Vol. 406. Springer-Verlag, 1974.
|
|
FORMULA
|
Let c(x) = (1-sqrt(1-4*x))/(2*x) = g.f. for Catalans (A000108), let d(x) = 1+x*c(x^2). Then g.f. is (x/6)*(c^3+2*subs(x=x^3, c)+3*d*subs(x=x^2, c)).
|
|
CROSSREFS
|
Sequence in context: A002841 A136509 A100664 this_sequence A045696 A091217 A068787
Adjacent sequences: A003443 A003444 A003445 this_sequence A003447 A003448 A003449
|
|
KEYWORD
|
nonn,easy,nice
|
|
AUTHOR
|
njas
|
|
|
Search completed in 0.002 seconds
|
