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 A339232 #7 Nov 30 2020 08:57:22
%S A339232 0,1,5,23,99,433,1880,8238,36202,159898,708517,3150128,14042620,
%T A339232 62751693,280997846,1260635337,5664870696,25493707908,114882350739,
%U A339232 518318733052,2341079272919,10584488664085,47898510357544,216940538748652,983326680302665,4460343301915203
%N A339232 Total number of interior vertices in the multigraphs of all oriented series-parallel networks with n edges.
%C A339232 See A339231 for additional details.
%F A339232 a(n) = Sum_{k=1..n-1} k*A339231(n,k).
%o A339232 (PARI) \\ See A339231 for VertexWeighted.
%o A339232 seq(n)={subst(deriv(VertexWeighted(n,y)), y, 1)}
%Y A339232 Cf. A003430, A339231.
%K A339232 nonn
%O A339232 1,3
%A A339232 _Andrew Howroyd_, Nov 29 2020