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 A338197 #38 May 23 2023 04:17:16 %S A338197 1,2,4,8,20,44,114,312,894,2639,8005,24362,74918,231123,722388, %T A338197 2276599,7242497,23144119,74203799,238684352 %N A338197 a(n) is the number of distinct resistances that can be obtained by a network of exactly n equal resistors, but not by any network with fewer than n equal resistors. %C A338197 See A180414 and A337517 for more information and references. %H A338197 Allan Gottlieb, <a href="https://cs.nyu.edu/~gottlieb/tr/overflow/2003-oct-3-more.html">Oct 3, 2003 addendum (Karnofsky)</a>. %H A338197 <a href="/index/Res#resistances">Index to sequences related to resistances</a>. %F A338197 a(n) = A180414(n) - A180414(n-1). %F A338197 a(n) = A051389(n) for n <= 5, a(n) > A051389(n) otherwise. %e A338197 a(6) = 44 because the resistances 11/13 and 13/11 (in units of resistor value) are representable in addition to the A051389(6)=42 resistances that can be achieved by only serial and parallel configurations with exactly 6 resistors and not by a network with fewer than 6 resistors. %Y A338197 Cf. A051389, A180414, A337517, A338487. %K A338197 nonn,hard,more %O A338197 1,2 %A A338197 _Hugo Pfoertner_, Nov 03 2020 %E A338197 a(15) corrected and a(16) added by _Hugo Pfoertner_, Dec 06 2020 %E A338197 a(17) from _Hugo Pfoertner_, Dec 09 2020 %E A338197 a(18) from _Hugo Pfoertner_, Apr 09 2021 %E A338197 a(19) from _Zhao Hui Du_, May 15 2023 %E A338197 a(20) from _Zhao Hui Du_, May 23 2023