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 A054051 #28 Mar 08 2021 22:48:27
%S A054051 1,9,119,2662,79154,2962062,132536919,6904606698,410379198542,
%T A054051 27406396140548,2031843175944876,165592123280454675,
%U A054051 14715292998356150461,1416127682894394114138,146723247630856311651736,16284075762705841850155071,1927434528878738556115924081,242361176791511465207020367116
%N A054051 Number of nonisomorphic connected binary n-state automata.
%C A054051 Inverse Euler transform of A054050.
%D A054051 F. Harary and E. Palmer, Graphical Enumeration, 1973. [See Section 6.5, pp. 146-150.]
%H A054051 Christian G. Bower, <a href="https://oeis.org/transforms_pari.txt">PARI programs for transforms</a>, 2007.
%H A054051 Michael A. Harrison, <a href="http://dx.doi.org/10.4153/CJM-1965-010-9">A census of finite automata</a>, Canad. J. Math., 17, No. 1 (1965), 100-113. [See Theorem 6.1 (p. 107) with k = 2 and p = 1 and Theorem 7.2 (p. 110). See also Table I on p. 110.]
%H A054051 N. J. A. Sloane, <a href="/transforms.txt">Maple programs for transforms</a>, 2001-2020.
%o A054051 (PARI) /* This program is a modification of _Christian G. Bower_'s PARI program for the inverse Euler transform from the link above. */
%o A054051 lista(nn) = {local(A=vector(nn+1)); for(n=1, nn+1, A[n]=if(n==1, 1, A054050(n-1))); local(B=vector(#A-1, n, 1/n), C); A[1] = 1; C = log(Ser(A)); A=vecextract(A, "2.."); for(i=1, #A, A[i] = polcoeff(C, i)); A = dirdiv(A, B); } \\ _Petros Hadjicostas_, Mar 08 2021
%Y A054051 Cf. A054050, A054745, A054746.
%K A054051 nonn
%O A054051 1,2
%A A054051 _Vladeta Jovovic_, Apr 29 2000
%E A054051 Terms a(16)-a(18) from _Petros Hadjicostas_, Mar 08 2021