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A006683 Number of regions in certain maps.
(Formerly M0560)
0
1, 2, 3, 4, 6, 8, 11, 15, 21, 28, 39, 53, 99, 137, 186 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

REFERENCES

Gustavus J. Simmons, The ochromatic number of planar graphs, pp. 295-316 of F. Harary and J. S. Maybee, editors, Graphs and Applications. Wiley, NY, 1985.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=1..15.

CROSSREFS

Sequence in context: A046935 A241334 A095814 * A014213 A064323 A003411

Adjacent sequences:  A006680 A006681 A006682 * A006684 A006685 A006686

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified October 1 04:06 EDT 2020. Contains 337441 sequences. (Running on oeis4.)