%I A006057 M3028
%S A006057 1,1,3,16,137,1826,37777,1214256,60075185,4484316358,493489876721,
%T A006057 78456654767756,17735173202222665,5630684018989523274,
%U A006057 2486496790249207981169,1515191575312017416011456
%N A006057 Number of labeled topologies with n points.
%D A006057 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A006057 M. Erne', Struktur- und Anzahlformeln fuer Topologien auf Endlichen Mengen, 
               Manuscripta Math., 11 (1974), 221-259.
%H A006057 Herman Jamke (hermanjamke(AT)fastmail.fm), Mar 02 2008, <a href="b006057.txt">
               Table of n, a(n) for n = 0..19</a>
%H A006057 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.
%F A006057 E.g.f.: A04(x)=exp(Z04(x)-1) where Z04(x) denotes the E.g.f. for A006059. 
               - Herman Jamke (hermanjamke(AT)fastmail.fm), Mar 02 2008
%Y A006057 Cf. A000798.
%Y A006057 Sequence in context: A119392 A129043 A135746 this_sequence A002719 A020554 
               A062874
%Y A006057 Adjacent sequences: A006054 A006055 A006056 this_sequence A006058 A006059 
               A006060
%K A006057 nonn,nice
%O A006057 0,3
%A A006057 N. J. A. Sloane (njas(AT)research.att.com).
%E A006057 More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Mar 02 2008