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 A340028 #10 Jan 09 2021 22:11:09
%S A340028 0,1,1,7,55,655,11147,287791,11787747,804475261,94875366649,
%T A340028 19825870580671,7466490852631207,5129453728126116131,
%U A340028 6487332587944013948099,15213161506747424007012971,66536415576917924594383104139,545371527333985035460963541248785
%N A340028 Number of unlabeled 2-connected graphs with n vertices rooted at a pair of noninterchangeable vertices.
%H A340028 Andrew Howroyd, <a href="/A340028/b340028.txt">Table of n, a(n) for n = 1..30</a>
%o A340028 (PARI) \\ See A004115 for graphsSeries and A339645 for combinatorial species functions.
%o A340028 cycleIndexSeries(n)={my(g=graphsSeries(n), gcr=sPoint(g)/g); x*sPoint(sSolve( sLog( gcr/(x*sv(1)) ), gcr ))}
%o A340028 { my(N=15); Vec(OgfSeries(cycleIndexSeries(N)), -N) }
%Y A340028 Cf. A002218, A004115, A241768, A304070, A304074, A340029.
%K A340028 nonn
%O A340028 1,4
%A A340028 _Andrew Howroyd_, Jan 02 2021