A345246 Number of 2-connected unlabeled simple graphs with no triangles.

1, 2, 6, 16, 78, 415, 3374, 35860, 524386, 10193061, 263036202, 8948113645, 400280198048

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,more

Author

Brendan McKay, Jun 12 2021

Status

approved