This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A123869 Order of minimal triangulation of the orientable closed surface of genus n (S_n). 1
 4, 7, 10, 10, 11, 12, 12, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18, 19, 19, 19, 20, 20, 21, 21, 21, 22, 22, 22, 23, 23, 23, 24, 24, 24, 24, 25, 25, 25, 26, 26, 26, 26, 27, 27, 27, 27, 28, 28, 28, 28, 29, 29, 29, 29, 30, 30, 30, 30, 31, 31, 31, 31, 31, 32, 32, 32, 32, 33, 33, 33, 33, 33 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Number of vertices in a triangulation of the orientable closed surface S_n of genus n that has the smallest number of vertices. REFERENCES J. L. Gross and J. Yellen, eds., Handbook of Graph Theory, CRC Press, 2004; p. 742, Fact F19. M. Jungerman and G. Ringel, Minimal triangulations on orientable surfaces, Acta Math. 145 (1980), 121-154. Ringel, Gerhard. Wie man die geschlossenen nichtorientierbaren Flächen in möglichst wenig Dreiecke zerlegen kann. (German) Math. Ann. 130 (1955), 317--326. MR0075591 (17,774b) LINKS FORMULA Ceil( (7+sqrt(1+48*n))/2 ), except a(2) = 10. CROSSREFS See A250098 for number of triangles in a minimal triangulation. Sequence in context: A118517 A282848 A093465 * A072125 A223024 A275340 Adjacent sequences:  A123866 A123867 A123868 * A123870 A123871 A123872 KEYWORD nonn AUTHOR N. J. A. Sloane, Nov 19 2006 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified November 20 06:06 EST 2018. Contains 317385 sequences. (Running on oeis4.)