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 A166638 #14 Feb 05 2025 07:50:39
%S A166638 1,8,16,64,32,128,48,512,256,256,80,1024,96,384,512,4096,128,2048,144,
%T A166638 2048,768,640,176,8192,1024,768,4096,3072,224,4096,240,32768,1280,
%U A166638 1024,1536,16384,288,1152,1536,16384,320,6144,336,5120,8192,1408,368,65536
%N A166638 Totally multiplicative sequence with a(p) = 8*(p-1) for prime p.
%H A166638 G. C. Greubel, <a href="/A166638/b166638.txt">Table of n, a(n) for n = 1..10000</a>
%F A166638 Multiplicative with a(p^e) = (8*(p-1))^e. If n = Product p(k)^e(k) then a(n) = Product (8*(p(k)-1))^e(k).
%F A166638 a(n) = A165829(n) * A003958(n) = 8^bigomega(n) * A003958(n) = 8^A001222(n) * A003958(n).
%t A166638 DirichletInverse[f_][1] = 1/f[1]; DirichletInverse[f_][n_] :=
%t A166638 DirichletInverse[f][n] = -1/f[1]*Sum[f[n/d]*DirichletInverse[f][d], {d, Most[Divisors[n]]}]; muphi[n_] := MoebiusMu[n]*EulerPhi[n]; a[m_] := DirichletInverse[muphi][m]; Table[a[m]*8^(PrimeOmega[m]), {m, 1, 100}] (* _G. C. Greubel_, May 20 2016 *)
%t A166638 f[p_, e_] := (8*(p-1))^e; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* _Amiram Eldar_, Oct 17 2023 *)
%Y A166638 Cf. A003958, A001222, A165829.
%K A166638 nonn,easy,mult
%O A166638 1,2
%A A166638 _Jaroslav Krizek_, Oct 18 2009