The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A135327 Number of triangulated surfaces (of any genus) with n vertices. 0
 1, 0, 1, 3, 21, 586, 50531, 16141671 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,4 LINKS Gennaro Amendola, Decomposition and Enumeration of Triangulated Surfaces, Experiment. Math. 17-2 (2008), 153-166, arXiv:0705.1835 [math.CO] table 2, page 20. EXAMPLE a(3) = 1 because the unique surface with 3 vertices is on the closed surface S^2. a(4) = 0 because there are no surface with 4 vertices in Amendola's table. a(5) = 1 because the unique surface with 5 vertices is on the closed surface RP^2. a(6) = 3 because there is a unique surface with 6 vertices on the closed surface T^2 and two on RP^2, so 1 + 2 = 3. a(7) = 21 because there are 5 surfaces with 7 vertices on the closed surface T^2, 6 on RP^2 and 10 on K^2, so 5 + 6 + 10 = 21. a(8) = 46 + 11 + 108 + 284 + 134 + 3 = 586 (see table). a(9) = 230 + 1261 + 59 + 28 + 597 + 6919 + 18166 + 18199 + 4994 + 78 = 50531 (see table). a(10) = 1513 + 50878 + 99177 + 3892 + 356 + 3864 + 82588 + 713714 + 3006044 + 5672821 + 4999850 + 1453490 + 53484 = 16141671. CROSSREFS Cf. A108239. Sequence in context: A014375 A135748 A145386 * A128679 A292331 A111432 Adjacent sequences:  A135324 A135325 A135326 * A135328 A135329 A135330 KEYWORD nonn,more AUTHOR Jonathan Vos Post, Dec 06 2007 EXTENSIONS Edited by N. J. A. Sloane, Dec 07 2007 Missing a(5) = 1 inserted by Andrey Zabolotskiy, Nov 20 2017 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 4 16:34 EDT 2020. Contains 336202 sequences. (Running on oeis4.)