%I #11 Mar 16 2023 19:46:43

%S 1,1,2,20,574,48854,12444800,9849180230,25265372689314,

%T 218451490123178684,6562780921564838071734,

%U 700270642102506752862044142,269621199012416753533007480951824,378982029174285293421133982496722212766,1962119228020498122395242424575089505014761082

%N Number of digraphs on n unlabeled nodes with a global source and sink.

%H Andrew Howroyd, <a href="/A350794/b350794.txt">Table of n, a(n) for n = 1..50</a>

%H Andrew Howroyd, <a href="/A350794/a350794_1.txt">PARI Program</a>, Jan 2022, updated Mar 2023.

%o (PARI) A350794seq(15) \\ See link for program code.

%Y The labeled version is A350790.

%Y Row sums of A350795.

%Y Cf. A049531, A051421, A345258, A350360, A350796.

%K nonn

%O 1,3

%A _Andrew Howroyd_, Jan 19 2022