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Number of unlabeled acyclic digraphs with n arcs and a global source and sink.
4

%I #7 Jan 09 2022 22:22:06

%S 1,1,1,2,5,14,44,153,584,2414,10732,50909,256198,1360645,7593530,

%T 44366458,270517289,1716555943,11308051214,77170484915,544525867544,

%U 3965944595335,29769162604337,229970873746105,1826057472681595,14886348784740516

%N Number of unlabeled acyclic digraphs with n arcs and a global source and sink.

%H Andrew Howroyd, <a href="/A350492/b350492.txt">Table of n, a(n) for n = 0..40</a>

%o (PARI) A350492seq(20) \\ See PARI link in A122078 for program code.

%Y Column sums of A350491.

%Y Cf. A122078, A345258, A350451, A350490.

%K nonn

%O 0,4

%A _Andrew Howroyd_, Jan 08 2022