%I
%S 1,0,1,1,0,0,2,4,4,1,1,0,0,0,4,16,34,46,38,27,13,5,1,1,0,0,0,0,9,56,
%T 229,573,1058,1448,1653,1487,1153,707,379,154,61,16,5,1,1
%N Triangle T(n,k) of number of digraphs with a source on n unlabeled nodes with k arcs, k=0,1,..,n*(n1).
%e [1], [0, 1, 1], [0, 0, 2, 4, 4, 1, 1], [0, 0, 0, 4, 16, 34, 46, 38, 27, 13, 5, 1, 1], ....
%e Number of digraphs with a source on 3 unlabeled nodes is 12=2+4+4+1+1.
%Y Row sums give A051421. Cf. A057270A057276, A057278A057279.
%K more,nonn,tabf
%O 1,7
%A _Vladeta Jovovic_, Goran Kilibard, Sep 14 2000
