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A207410 Number of connected triangle-free graphs on n nodes with edge chromatic number 4. 2
0, 0, 0, 0, 1, 4, 25, 136, 772, 4953, 35340, 288335, 2632792, 26726855, 296550560 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

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

CROSSREFS

Cf. A207408.

Sequence in context: A273120 A220381 A015533 * A278275 A301836 A275177

Adjacent sequences:  A207407 A207408 A207409 * A207411 A207412 A207413

KEYWORD

nonn,more

AUTHOR

Michael Sollami, Feb 17 2012

STATUS

approved

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Last modified December 1 16:44 EST 2021. Contains 349430 sequences. (Running on oeis4.)