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 A166661 #8 May 22 2016 12:56:12
%S A166661 1,7,10,49,16,70,22,343,100,112,34,490,40,154,160,2401,52,700,58,784,
%T A166661 220,238,70,3430,256,280,1000,1078,88,1120,94,16807,340,364,352,4900,
%U A166661 112,406,400,5488,124,1540,130,1666,1600,490,142,24010,484,1792
%N A166661 Totally multiplicative sequence with a(p) = 3p+1 for prime p.
%H A166661 G. C. Greubel, <a href="/A166661/b166661.txt">Table of n, a(n) for n = 1..10000</a>
%F A166661 Multiplicative with a(p^e) = (3p+1)^e. If n = Product p(k)^e(k) then a(n) = Product (3*p(k)+1)^e(k).
%t A166661 a[1] = 1; a[n_] := (fi = FactorInteger[n]; Times @@ ((3*fi[[All, 1]] + 1)^fi[[All, 2]])); Table[a[n], {n, 1, 100}] (* _G. C. Greubel_, May 22 2016 *)
%K A166661 nonn,mult
%O A166661 1,2
%A A166661 _Jaroslav Krizek_, Oct 18 2009