%I A011819
%S A011819 2,5,16,52,152,392,904,1899,3694,6743,11672,19318,30772,47426,71024,
%T A011819 103717,148122,207385,285248,386120,515152,678316,882488,1135535,
%U A011819 1446406,1825227,2283400,2833706,3490412,4269382,5188192,6266249
%N A011819 M-sequences m_0,m_1,m_2,m_3 with m_1 < n.
%D A011819 S. Linusson, The number of M-sequences and f-vectors, Combinatorica, 
               19 (1999), 255-266.
%F A011819 a(n)= ( 2*n^6 +15*n^5 +50*n^4 +165*n^3 +308*n^2 +540*n +720 )/360, (frank.ellermann(AT)t-online.de).
%Y A011819 Cf. A011820 ... A011825, A011827.
%Y A011819 Sequence in context: A148388 A148389 A108529 this_sequence A148390 A148391 
               A148392
%Y A011819 Adjacent sequences: A011816 A011817 A011818 this_sequence A011820 A011821 
               A011822
%K A011819 nonn
%O A011819 1,1
%A A011819 Svante Linusson (linusson(AT)math.kth.se)