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 A338402 #15 Oct 29 2020 18:49:13 %S A338402 3,9,7,123,1773,21075,68761,4989753,178945525,396450465051, %T A338402 144693391952079,4833128874789907,751463705427149325, %U A338402 59315127102256318272081,30288529373611329886681,335082000330404529286853990499,6485606445639875637410148108213,7842015457241561891262053489240216057 %N A338402 a(n) is the denominator of the resistance R(n) = A338401(n)/a(n) of a triangular network of 3*n*(n+1)/2 one Ohm resistors in a hexagonal lattice arrangement. %C A338402 For more information and example see A338401. %H A338402 Hugo Pfoertner, <a href="/A338402/b338402.txt">Table of n, a(n) for n = 1..50</a> %Y A338402 Cf. A338401. %K A338402 nonn,frac %O A338402 1,1 %A A338402 _Hugo Pfoertner_, Oct 24 2020