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 A347108 #8 Aug 18 2021 09:29:31
%S A347108 3,24,72,177,285,621,813,1278,1785,2541,2973,4653,5241,6585,8313,
%T A347108 10266,11238,14787,15987,19767,22839,25863,27591,35031,37914,42030,
%U A347108 46830,53550,56250,68346,71418,79419,86331,93135,100047,117792,122124,130524,139932,156672
%N A347108 a(n) = Sum_{k=1..n} sigma(k)*sigma(2*k), where sigma(n) = A000203(n) is the sum of the divisors of n.
%F A347108 a(n) ~ 2*zeta(3)*n^3.
%t A347108 Accumulate[Table[DivisorSigma[1,k] * DivisorSigma[1,2*k], {k, 1, 100}]]
%o A347108 (PARI) a(n) = sum(k=1, n, sigma(k)*sigma(2*k)); \\ _Michel Marcus_, Aug 18 2021
%Y A347108 Cf. A000203, A024916, A065764, A072379, A074285, A326123, A326124, A330322, A346865.
%K A347108 nonn
%O A347108 1,1
%A A347108 _Vaclav Kotesovec_, Aug 18 2021