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A326224 Number of unlabeled n-vertex digraphs (with loops) not containing a Hamiltonian path. 10
1, 2, 3, 30, 649 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

A directed path is Hamiltonian if it passes through every vertex exactly once.

LINKS

Table of n, a(n) for n=0..4.

Wikipedia, Hamiltonian path

Gus Wiseman, Enumeration of paths and cycles and e-coefficients of incomparability graphs.

Gus Wiseman, Non-isomorphic representatives of the a(3) = 30 digraphs not containing a Hamiltonian path.

FORMULA

A000595(n) = a(n) + A326221(n).

CROSSREFS

The labeled case is A326213.

The undirected case is A283420 (without loops).

Unlabeled digraphs containing a Hamiltonian path are A326221.

Unlabeled digraphs not containing a Hamiltonian cycle are A326223.

Cf. A000595, A002416, A003087, A003216, A057864.

Sequence in context: A203431 A137981 A110351 * A270483 A217370 A088115

Adjacent sequences:  A326221 A326222 A326223 * A326225 A326226 A326227

KEYWORD

nonn,more

AUTHOR

Gus Wiseman, Jun 16 2019

STATUS

approved

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Last modified July 23 20:32 EDT 2019. Contains 325264 sequences. (Running on oeis4.)