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 A034488 #33 Jun 29 2025 21:30:27
%S A034488 4,12,50,252,1394,8052,47450,282252,1686434,10097892,60526250,
%T A034488 362976252,2177317874,13062296532,78368963450,470199366252,
%U A034488 2821153019714,16926788715972,101560344351050,609360902796252,3656161927895954,21936961102828212
%N A034488 Sum of n-th powers of divisors of 6.
%H A034488 T. D. Noe, <a href="/A034488/b034488.txt">Table of n, a(n) for n=0..200</a>
%H A034488 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (12,-47,72,-36).
%F A034488 a(n) = 1^n + 2^n + 3^n + 6^n.
%F A034488 G.f.: -2*(36*x^3 - 47*x^2 + 18*x - 2) / ((x - 1)*(2*x - 1)*(3*x - 1)*(6*x - 1)). - _Colin Barker_, Apr 20 2014
%t A034488 a[n_] := (2^n + 1)*(3^n + 1); Table[a[n], {n, 0, 19}] (* _Zerinvary Lajos_, Mar 25 2007 *)
%t A034488 Total[#^Range[0, 20]&/@Divisors[6]] (* _Vincenzo Librandi_, Apr 17 2014 *)
%o A034488 (Sage) [sigma(6,n)for n in range(0,20)] # _Zerinvary Lajos_, Jun 04 2009
%o A034488 (PARI) a(n)=6^n+3^n+2^n+1 \\ _Charles R Greathouse IV_, Apr 28 2011
%o A034488 (Magma) [DivisorSigma(n, 6): n in [0..20]]; // _Vincenzo Librandi_, Apr 17 2014
%K A034488 nonn,easy
%O A034488 0,1
%A A034488 _N. J. A. Sloane_
%E A034488 More terms from _Colin Barker_, Apr 20 2014