%I A000665 M1550 N0606
%S A000665 1,1,2,5,34,2136,7013320,1788782616656,53304527811667897248,
%T A000665 366299663432194332594005123072,
%U A000665 1171638318502989084030402509596875836036608
%N A000665 Number of 3-uniform hypergraphs on n unlabeled nodes, or equivalently 
               number of relations with 3 arguments on n nodes.
%D A000665 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A000665 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 
               (includes this sequence).
%D A000665 F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 
               1973, p. 231.
%D A000665 W. Oberschelp, Kombinatorische Anzahlbestimmungen in Relationen, Math. 
               Ann., 174 (1967), 53-78.
%D A000665 E. M. Palmer, On the number of n-plexes, Discrete Math., 6 (1973), 377-390.
%H A000665 P. J. Cameron, <a href="http://www.cs.uwaterloo.ca/journals/JIS/index.html">
               Sequences realized by oligomorphic permutation groups</a>, J. Integ. 
               Seqs. Vol. 3 (2000), #00.1.5.
%Y A000665 A diagonal of A092337.
%Y A000665 Sequence in context: A027303 A052695 A002665 this_sequence A058882 A000659 
               A164919
%Y A000665 Adjacent sequences: A000662 A000663 A000664 this_sequence A000666 A000667 
               A000668
%K A000665 nonn,nice
%O A000665 1,3
%A A000665 N. J. A. Sloane (njas(AT)research.att.com).
%E A000665 Corrected and extended by Vladeta Jovovic (vladeta(AT)eunet.rs)