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A345246 Number of 2-connected unlabeled simple graphs with no triangles. 1
1, 2, 6, 16, 78, 415, 3374, 35860, 524386, 10193061, 263036202, 8948113645, 400280198048 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,2

LINKS

Table of n, a(n) for n=4..16.

EXAMPLE

For n=4 the only example is a 4-cycle.

CROSSREFS

Cf. A002218 all 2-connected graphs.

Cf. A024607 all connected triangle-free graphs.

Sequence in context: A147905 A147897 A147889 * A137858 A074740 A204436

Adjacent sequences:  A345243 A345244 A345245 * A345247 A345248 A345249

KEYWORD

nonn,hard

AUTHOR

Brendan McKay, Jun 12 2021

STATUS

approved

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Last modified September 23 20:42 EDT 2021. Contains 347617 sequences. (Running on oeis4.)