%I A053598
%S A053598 0,2,13,202,9390,1531336,880492496,1792477159408,13026163465206704,
%T A053598 341247403996148180800,32522568124623933138617088,
%U A053598 11366712907916015518547782806784
%N A053598 Number of n-node unlabeled digraphs without isolated nodes.
%C A053598 Equals first differences of A000273.
%Y A053598 Cf. A002494.
%Y A053598 Sequence in context: A049512 A003507 A003085 this_sequence A102585 A078702 
               A069569
%Y A053598 Adjacent sequences: A053595 A053596 A053597 this_sequence A053599 A053600 
               A053601
%K A053598 nonn,nice
%O A053598 0,2
%A A053598 Vladeta Jovovic (vladeta(AT)eunet.rs), Apr 10 2000