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 A363240 #22 Jul 11 2023 08:57:33 %S A363240 1,2,5,12,32,88,260,819,2680,8642,27976,88946,281541,893028,2841344, %T A363240 9092174,29176634,93854841,302611365 %N A363240 Number of distinct resistances that can be produced from a circuit that is a 2-connected loopless multigraph with n edges and each edge having a unit resistor. %C A363240 The resistances between any two nodes of the graph are counted. %C A363240 All resistances in A337517 can be obtained by serial combinations of resistances of one or more 2-connected loopless multigraphs. %e A363240 a(2)=1 since the only multigraph with 2 edges is a double edge graph which forms resistance 1/2. %e A363240 For n=4, there are a quadruple edge graph (resistance 1/4), a triangle graph with one double edge (2/5 between double edge and 3/5 between single edge) and square graph (3/4 between neighbor nodes and 1 between opposite nodes) so a(4)=5. %Y A363240 Cf. A010357, A337517. %K A363240 nonn,more %O A363240 2,2 %A A363240 _Zhao Hui Du_, May 23 2023