A003087 Number of acyclic digraphs with n unlabeled nodes.
1, 1, 2, 6, 31, 302, 5984, 243668, 20286025, 3424938010, 1165948612902, 797561675349580, 1094026876269892596, 3005847365735456265830, 16530851611091131512031070, 181908117707763484218885361402
Offset: 0
References
- F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 194.
- R. W. Robinson, Numerical implementation of graph counting algorithms, AGRC Grant, Math. Dept., Univ. Newcastle, Australia, 1976.
- N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
Links
- Andrew Howroyd, Table of n, a(n) for n = 0..50 (terms 0..18 were computed by R. W. Robinson; terms 19..36 by Sean A. Irvine, Jan 22 2014)
- Jack Kuipers and Giusi Moffa, Uniform generation of random acyclic digraphs, arXiv preprint arXiv:1202.6590 [stat.CO], 2012. - _N. J. A. Sloane_, Sep 14 2012
- B. D. McKay, F. E. Oggier, G. F. Royle, N. J. A. Sloane, I. M. Wanless and H. S. Wilf, Acyclic digraphs and eigenvalues of (0,1)-matrices, J. Integer Sequences, 7 (2004), #04.3.3.
- B. D. McKay, F. E. Oggier, G. F. Royle, N. J. A. Sloane, I. M. Wanless and H. S. Wilf, Acyclic digraphs and eigenvalues of (0,1)-matrices, arXiv:math/0310423 [math.CO], 2003.
- Lawrence Ong, Optimal Finite-Length and Asymptotic Index Codes for Five or Fewer Receivers, arXiv preprint arXiv:1606.05982 [cs.IT], 2016.
- R. W. Robinson, Counting unlabeled acyclic digraphs, in Little C.H.C. (Ed.), "Combinatorial Mathematics V (Melbourne 1976)", Lect. Notes Math. 622 (1976), pp. 28-43. DOI:10.1007/BFb0069178.
- R. W. Robinson, Enumeration of acyclic digraphs, Manuscript. (Annotated scanned copy)
- Eric Weisstein's World of Mathematics, Acyclic Digraph.
- Index entries for sequences related to binary matrices
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