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 A076375 #16 Dec 04 2019 09:59:30
%S A076375 1,3,6,15,35,70,105,210,357,420,1045,1485,2090,2970,3135,3339,5049,
%T A076375 5940,6270,10659,12441,12540,16065,24871,24969,29029,33915,35343,
%U A076375 39105,39585,49742,50065,58058,58435,64285,70686,71145,74613,78210,87087
%N A076375 Numbers k such that both k and 2*k are balanced numbers (A020492).
%H A076375 Amiram Eldar, <a href="/A076375/b076375.txt">Table of n, a(n) for n = 1..10000</a> (calculated using data from Jud McCranie, terms 1..1000 from Donovan Johnson)
%t A076375 f[x_] := DivisorSigma[1, x]/EulerPhi[x] Do[s=f[n]; s1=f[2*n]; If[IntegerQ[s]&&IntegerQ[s1], Print[n]], {n, 1, 100000}]
%Y A076375 Cf. A000010, A000203, A055234.
%K A076375 nonn
%O A076375 1,2
%A A076375 _Labos Elemer_, Oct 15 2002