|
Search: id:A000703
|
|
|
| A000703 |
|
Chromatic number (or Heawood number) of nonorientable surface with n crosscaps.
(Formerly M3265 N1318)
|
|
+0
2
|
|
| 4, 6, 7, 7, 8, 9, 9, 10, 10, 10, 11, 11, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18, 18, 19, 19, 19, 19, 19, 19, 20, 20, 20, 20, 20, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24
(list; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
REFERENCES
|
K. Appel and W. Haken, Every planar map is four colorable. I. Discharging. Illinois J. Math. 21 (1977), no. 3, 429-490.
G. A. Dirac, Map-color theorems, Canad. J. Math., 4 (1952), 480ff.
J. L. Gross and T. W. Tucker, Topological Graph Theory, Wiley, 1987; see Table 5.2 p. 221.
G. Ringel and J. W. T. Youngs, Solution of the Heawood map-coloring problem, Proc. Nat. Acad. Sci. USA, 60 (1968), 438-445.
J. L. Gross and J. Yellen, eds., Handbook of Graph Theory, CRC Press, 2004; p. 368 and 631.
|
|
LINKS
|
T. D. Noe, Table of n, a(n) for n=0..1000
G. Ringel & J. W. T. Youngs, Solution Of The Heawood Map-Coloring Problem
|
|
FORMULA
|
a(n) = floor((7+sqrt(1+24*n))/2).
|
|
CROSSREFS
|
Cf. A000934 (the orientable case).
Sequence in context: A135798 A021218 A019605 this_sequence A011275 A006185 A021876
Adjacent sequences: A000700 A000701 A000702 this_sequence A000704 A000705 A000706
|
|
KEYWORD
|
nonn,nice
|
|
AUTHOR
|
njas
|
|
|
Search completed in 0.002 seconds
|
