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 A007100 M5343 #18 Jul 08 2025 16:59:43
%S A007100 1,70,16800,9238320,9520156800,16305064776000,42856575521760000,
%T A007100 163329351308323200000,864876880105205071104000,
%U A007100 6155146233167046820024320000,57316399761348433188962519040000
%N A007100 Number of labeled trivalent (or cubic) 3-connected graphs with 2n nodes.
%D A007100 R. W. Robinson, personal communication.
%D A007100 R. W. Robinson, Numerical implementation of graph counting algorithms, AGRC Grant, Math. Dept., Univ. Newcastle, Australia, 1976.
%D A007100 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A007100 R. W. Robinson, <a href="/A007100/b007100.txt">Table of n, a(n) for n = 2..28</a>
%H A007100 R. W. Robinson, <a href="/A002829/a002829.pdf">Cubic labeled graphs, computer print-out, n.d.</a> (see last page)
%F A007100 a(n) = (2*n)!*r(n)/(3*n*2^n) where r(2) = 1 and r(n) = (3*n-2) * (r(n-1) + Sum_{i=2..n-2} r(i) * r(n-i)). - _Sean A. Irvine_, Oct 11 2017
%K A007100 nonn
%O A007100 2,2
%A A007100 _N. J. A. Sloane_