The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A326221 Number of unlabeled n-vertex digraphs (with loops) containing a Hamiltonian path. 9
 0, 0, 7, 74, 2395 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 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, arXiv:0709.0430 [math.CO], 2007. Gus Wiseman, Non-isomorphic representatives of the a(3) = 74 digraphs containing a Hamiltonian path. FORMULA A000595(n) = a(n) + A326224(n). CROSSREFS The labeled case is A326214. The undirected case is A057864 (without loops). Unlabeled digraphs not containing a Hamiltonian path are A326224. Unlabeled digraphs containing a Hamiltonian cycle are A326226. Cf. A000595, A002416, A003087, A003216, A283420. Sequence in context: A054745 A323322 A356589 * A197091 A174243 A157706 Adjacent sequences: A326218 A326219 A326220 * A326222 A326223 A326224 KEYWORD nonn,more AUTHOR Gus Wiseman, Jun 16 2019 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 16 17:08 EDT 2024. Contains 371749 sequences. (Running on oeis4.)