%I A004251 M1250
%S A004251 1,2,4,11,31,102,342,1213,4361,16016,59348,222117,836315,3166852,
%T A004251 12042620,45967479,176005709,675759564,2600672458
%N A004251 Number of graphical partitions (degree-vectors for simple graphs with 
               n vertices, or possible ordered row-sum vectors for a symmetric 0-1 
               matrix with diagonal values 0).
%D A004251 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A004251 R. A. Brualdi, H. J. Ryser, Combinatorial Matrix Theory, Cambridge Univ. 
               Press, 1992.
%D A004251 P. R. Stein, On the number of graphical partitions, pp. 671-684 of Proc. 
               9th S-E Conf. Combinatorics, Graph Theory, Computing, Congr. Numer. 
               21 (1978).
%H A004251 T. M. Barnes and C. D. Savage, A recurrence for counting graphical partitions, 
               <a href="http://www.combinatorics.org/">Electronic J. Combinatorics</
               a>, 2 (1995)
%H A004251 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               DegreeSequence.html">Link to a section of The World of Mathematics.</
               a>
%H A004251 <a href="Sindx_Gra.html#graph_part">Index entries for sequences related 
               to graphical partitions</a>
%H A004251 Author?, <a href="http://www.geocities.jp/sk_graph/degseq-2.pdf">Title?</
               a>.
%Y A004251 Cf. A000569, A004250, A004251, A029889.
%Y A004251 Sequence in context: A148166 A148167 A148168 this_sequence A148169 A110140 
               A115625
%Y A004251 Adjacent sequences: A004248 A004249 A004250 this_sequence A004252 A004253 
               A004254
%K A004251 nonn,more
%O A004251 1,2
%A A004251 N. J. A. Sloane (njas(AT)research.att.com).
%E A004251 More terms from TORSTEN.SILLKE(AT)LHSYSTEMS.COM, using Cor. 6.3.3, Th. 
               6.3.6, Cor. 6.2.5 of Brualdi-Ryser.
%E A004251 a(19) from Herman Jamke (hermanjamke(AT)fastmail.fm), May 19 2007