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 A283420 Number of simple (not necessarily connected) untraceable graphs on n nodes. 18
 0, 1, 2, 6, 16, 65, 310, 2316, 26241, 522596, 18766354 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Table of n, a(n) for n=1..11. Eric Weisstein's World of Mathematics, Untraceable Graph Wikipedia, Hamiltonian path Gus Wiseman, Enumeration of paths and cycles and e-coefficients of incomparability graphs, arXiv:0709.0430 [math.CO], 2007. Gus Wiseman, The a(5) = 16 unlabeled simple graphs not containing a Hamiltonian path. FORMULA a(n) = A000088(n) - A057864(n). CROSSREFS Cf. A000088 (number of simple graphs on n vertices). Cf. A057864 (number of simple traceable graphs on n vertices). Cf. A283421 (number of simple connected untraceable graphs on n vertices). The labeled case is A326205. The directed case is A326224 (with loops). Unlabeled simple graphs not containing a Hamiltonian cycle are A246446. Cf. A003216, A326206, A326217, A326221. Sequence in context: A173994 A363587 A150032 * A121749 A009386 A009605 Adjacent sequences: A283417 A283418 A283419 * A283421 A283422 A283423 KEYWORD nonn,more AUTHOR Eric W. Weisstein, May 14 2017 STATUS approved

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Last modified May 21 11:30 EDT 2024. Contains 372736 sequences. (Running on oeis4.)