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A126738 Number of connected graphs on n nodes with chromatic number 4. 0
0, 0, 0, 1, 3, 26, 282, 5009, 149551, 7694428, 667036310 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

Table of n, a(n) for n=1..11.

Keith M. Briggs, Combinatorial Graph Theory

CROSSREFS

A diagonal of triangle in A126736.

Sequence in context: A048861 A053972 A204561 * A109074 A227020 A119293

Adjacent sequences:  A126735 A126736 A126737 * A126739 A126740 A126741

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Feb 16 2007

EXTENSIONS

a(11) from Michael Sollami, Jan 29 2012.

STATUS

approved

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Last modified December 21 19:36 EST 2014. Contains 252325 sequences.