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 A166662 #8 May 22 2016 12:56:20
%S A166662 1,9,13,81,21,117,29,729,169,189,45,1053,53,261,273,6561,69,1521,77,
%T A166662 1701,377,405,93,9477,441,477,2197,2349,117,2457,125,59049,585,621,
%U A166662 609,13689,149,693,689,15309,165,3393,173,3645,3549,837,189,85293,841,3969
%N A166662 Totally multiplicative sequence with a(p) = 4p+1 for prime p.
%H A166662 G. C. Greubel, <a href="/A166662/b166662.txt">Table of n, a(n) for n = 1..10000</a>
%F A166662 Multiplicative with a(p^e) = (4p+1)^e. If n = Product p(k)^e(k) then a(n) = Product (4*p(k)+1)^e(k).
%t A166662 a[1] = 1; a[n_] := (fi = FactorInteger[n]; Times @@ ((4*fi[[All, 1]] + 1)^fi[[All, 2]])); Table[a[n], {n, 1, 100}] (* _G. C. Greubel_, May 22 2016 *)
%K A166662 nonn,mult
%O A166662 1,2
%A A166662 _Jaroslav Krizek_, Oct 18 2009