A330346 Number of unlabeled simple graphs covering n vertices with exactly two automorphisms.

0, 0, 1, 1, 2, 9, 37

Offset: 0

Author

Gus Wiseman, Dec 12 2019

Keywords

• nonn
• more

Comments

First differs from A241454 at n = 8.

Examples

			Non-isomorphic representatives of the a(5) = 9 graphs:
  {12,13,14,25}
  {12,13,24,35}
  {12,13,14,23,25}
  {12,13,14,23,45}
  {12,13,15,24,34}
  {12,13,14,15,23,24}
  {12,13,14,23,24,35}
  {12,13,14,23,25,45}
  {12,13,14,15,23,24,35}
		

Links

• Gus Wiseman, The a(5) = 9 graphs with exactly two automorphisms.

Crossrefs

The labeled version is A330297.

The non-covering version is A330344.

Unlabeled covering graphs are A002494.

Unlabeled connected graphs with exactly two automorphisms are A241454.

Graphs with exactly two automorphisms are A330297 (labeled covering), A330344 (unlabeled), A330345 (labeled), A330346 (unlabeled covering), A241454 (unlabeled connected).

Cf. A000088, A003400, A055621, A124059, A330098, A330227, A330230, A330231, A330294, A330295, A330343.