%I A136564
%S A136564 1,1,1,5,4,1,1,9,21,16,4,1,1,18,71,108,71,22,4,1,1,27,194,491,557,326,
%T A136564 101,22,4,1,1,43,476,1903,3353,3062,1587,497,111,22,4,1,1,59,1030,6298,
%U A136564 16644,22352,17035,7982,2433,555,111,22,4,1,1,84,2095,18823,72064
%N A136564 Array read by rows: T(n,k) is the number of directed multigraphs with 
               loops with n arcs, k vertices and no vertex of degree 0.
%C A136564 Length of the n^th row: 2n.
%C A136564 T(n,1)=T(n,2n)=1 and T(n,2n-1)=4 if n>1.
%C A136564 Row sums: A052171.
%C A136564 Sums of the first 2 entries of each row: A005993.
%C A136564 Sums of the first 3 entries of each row: A050927.
%C A136564 Sums of the first 4 entries of each row: A050929.
%Y A136564 Sequence in context: A132707 A046575 A154739 this_sequence A136042 A166044 
               A087707
%Y A136564 Adjacent sequences: A136561 A136562 A136563 this_sequence A136565 A136566 
               A136567
%K A136564 nonn,tabl
%O A136564 1,4
%A A136564 Benoit Jubin (benoit_jubin(AT)yahoo.fr), Apr 14 2008
%E A136564 More terms from Benoit Jubin and Vladeta Jovovic (vladeta(AT)eunet.yu), 
               Sep 08 2008