login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A123870 Order of minimal triangulation of nonorientable closed surface with n cross-caps (N_n). 0
4, 6, 8, 9, 9, 9, 10, 10, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18, 18, 19, 19, 19, 19, 19, 20, 20, 20, 20, 20, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 25, 25, 25 (list; graph; refs; listen; history; internal format)
OFFSET

0,1

REFERENCES

J. L. Gross and J. Yellen, eds., Handbook of Graph Theory, CRC Press, 2004; p. 742.

FORMULA

Ceil( (7+sqrt(1+24*g))/2 ), except a(2) = 8, a(3) = 9.

CROSSREFS

Sequence in context: A077649 A132025 A200363 * A085049 A019516 A031977

Adjacent sequences:  A123867 A123868 A123869 * A123871 A123872 A123873

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), Nov 19 2006

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 15 05:45 EST 2012. Contains 205694 sequences.