%I A005387 M1493
%S A005387 1,2,5,16,62,276,1377,7596,45789,298626,2090910,15621640,123897413,
%T A005387 1038535174,9165475893,84886111212,822648571314,8321077557124,
%U A005387 87648445601429,959450073912136,10894692556576613,128114221270929646
%N A005387 Number of partitional matroids on n elements.
%D A005387 Recski, A.; Enumerating partitional matroids. Stud. Sci. Math. Hungar. 
               9 (1974), 247-249 (1975).
%D A005387 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%H A005387 T. D. Noe, <a href="b005387.txt">Table of n, a(n) for n=0..100</a>
%H A005387 <a href="Sindx_Mat.html#matroid">Index entries for sequences related 
               to matroids</a>
%F A005387 E.g.f.: exp ((x-1)*e^x + 2*x + 1 ).
%Y A005387 Sequence in context: A033543 A124531 A129578 this_sequence A138549 A144188 
               A157314
%Y A005387 Adjacent sequences: A005384 A005385 A005386 this_sequence A005388 A005389 
               A005390
%K A005387 nonn,easy,nice
%O A005387 0,2
%A A005387 N. J. A. Sloane (njas(AT)research.att.com).
%E A005387 More terms from James A. Sellers (sellersj(AT)math.psu.edu), Aug 21 2000