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%I #14 Jan 22 2022 16:24:42
%S 1,1,10,287,24427,6222400,4924590115,12632686344657,
%T 109225745061589342,3281390460782419035867,
%U 350135321051253376431022071,134810599506208376766503740475912,189491014587142646710566991248361106383,981059614010249061197621212287544752507380541
%N Number of rooted unlabeled strongly connected digraphs with n nodes.
%C There is a rather difficult formula (simplified in 1973). The subsequent published value 6222928 for n=6 needs to be verified.
%C The correct value is 6222400. Terms up to a(7) have been confirmed by brute force using digraphs generated by nauty. - _Andrew Howroyd_, Jan 12 2022
%H Andrew Howroyd, <a href="/A049387/b049387.txt">Table of n, a(n) for n = 1..50</a>
%H V. A. Liskovets, <a href="http://dx.doi.org/10.1007/BF01673687">The number of strongly connected directed graphs</a>, Mat. Notes, 8 (1970), 877-882
%o (PARI) \\ See PARI link in A350794 for program code.
%o A049387seq(15) \\ _Andrew Howroyd_, Jan 22 2022
%Y Cf. A035512, A350794.
%K nonn
%O 1,3
%A _Valery A. Liskovets_
%E Terms a(6) and beyond from _Andrew Howroyd_, Jan 12 2022
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