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 A386747 #17 Aug 03 2025 10:13:06
%S A386747 0,1,68,738,4368,15650,50184,117698,279616,538083,1064200,1771682,
%T A386747 3223584,4826978,8003464,11549700,17895680,24137858,36589644,47046242,
%U A386747 68359200,86861124,120474376,148036418,206356608,244531875,328234504,392263236,514104864,594824162
%N A386747 a(n) = n^2*sigma_4(n).
%H A386747 Vincenzo Librandi, <a href="/A386747/b386747.txt">Table of n, a(n) for n = 0..9000</a>
%F A386747 G.f.: Sum_{k>=1} k^6*x^k*(1 + x^k)/(1 - x^k)^3. - _Amiram Eldar_, Aug 01 2025
%F A386747 a(n) = n^2*A001159(n).
%F A386747 Dirichlet g.f.: zeta(s-2)*zeta(s-6).- _R. J. Mathar_, Aug 03 2025
%t A386747 Table[n^2*DivisorSigma[4, n], {n, 0, 40}]
%t A386747 nmax = 40; CoefficientList[Series[Sum[k^6*x^k*(1 + x^k)/(1 - x^k)^3, {k, 1, nmax}], {x, 0, nmax}], x]
%o A386747 (Magma) [0] cat [n^2*DivisorSigma(4, n): n in [1..35]]; // _Vincenzo Librandi_, Aug 02 2025
%Y A386747 Cf. A000290, A001159, A386749, A386748.
%K A386747 nonn,mult
%O A386747 0,3
%A A386747 _Vaclav Kotesovec_, Aug 01 2025