This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A049387 #14 Jan 22 2022 16:24:42 %S A049387 1,1,10,287,24427,6222400,4924590115,12632686344657, %T A049387 109225745061589342,3281390460782419035867, %U A049387 350135321051253376431022071,134810599506208376766503740475912,189491014587142646710566991248361106383,981059614010249061197621212287544752507380541 %N A049387 Number of rooted unlabeled strongly connected digraphs with n nodes. %C A049387 There is a rather difficult formula (simplified in 1973). The subsequent published value 6222928 for n=6 needs to be verified. %C A049387 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 A049387 Andrew Howroyd, <a href="/A049387/b049387.txt">Table of n, a(n) for n = 1..50</a> %H A049387 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 A049387 (PARI) \\ See PARI link in A350794 for program code. %o A049387 A049387seq(15) \\ _Andrew Howroyd_, Jan 22 2022 %Y A049387 Cf. A035512, A350794. %K A049387 nonn %O A049387 1,3 %A A049387 _Valery A. Liskovets_ %E A049387 Terms a(6) and beyond from _Andrew Howroyd_, Jan 12 2022