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 A340921 #12 Mar 15 2021 04:58:03 %S A340921 1,2,4,8,16,36,80,194,506,1400,4024,11870,35200,104836,311686,929088, %T A340921 2776618,8321128,24967712,74985708 %N A340921 a(n) is the number of distinct resistances that can be produced using at most n unit resistors in a planar network. %C A340921 The relation of this sequence to A340920 is the analog of the relation of A180414 to A337517. %F A340921 a(n) = A180414(n) for n <= 9, a(n) < A180414(n) for n >= 10. %Y A340921 Cf. A153588, A174284, A174286, A180414, A337517, A340920. %K A340921 nonn,more,hard %O A340921 0,2 %A A340921 _Hugo Pfoertner_ and _Rainer Rosenthal_, Feb 14 2021 %E A340921 a(19) from _Hugo Pfoertner_, Mar 15 2021