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 A386777 #15 Aug 04 2025 07:11:06
%S A386777 0,1,260,6570,66576,390650,1708200,5764850,17043520,43105851,
%T A386777 101569000,214359002,437404320,815730890,1498861000,2566570500,
%U A386777 4363141376,6975757730,11207521260,16983563402,26007914400,37875064500,55733340520,78310985810,111975926400,152597656875
%N A386777 a(n) = n^2*sigma_6(n).
%H A386777 Vincenzo Librandi, <a href="/A386777/b386777.txt">Table of n, a(n) for n = 0..10000</a>
%F A386777 G.f.: Sum_{k>=1} k^8*x^k*(1 + x^k)/(1 - x^k)^3.
%F A386777 a(n) = n^2*A013954(n).
%F A386777 Dirichlet g.f.: zeta(s-2)*zeta(s-8). - _R. J. Mathar_, Aug 03 2025
%t A386777 Table[n^2*DivisorSigma[6, n], {n, 0, 30}]
%t A386777 nmax = 30; CoefficientList[Series[Sum[k^8*x^k*(1 + x^k)/(1 - x^k)^3, {k, 1, nmax}], {x, 0, nmax}], x]
%o A386777 (Magma) [0] cat [n^2*DivisorSigma(6, n): n in [1..35]]; // _Vincenzo Librandi_, Aug 04 2025
%Y A386777 Cf. A282097, A386745, A282099, A386747, A282751, A282753, A386778.
%Y A386777 Cf. A013954, A386750.
%K A386777 nonn,mult
%O A386777 0,3
%A A386777 _Vaclav Kotesovec_, Aug 02 2025