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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
OFFSET
4,2
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 A374826
KEYWORD
nonn,hard,more
AUTHOR
Brendan McKay, Jun 12 2021
STATUS
approved