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 A174688 #28 Nov 21 2020 06:59:00
%S A174688 1,3,5,9,15,17,25,27,45,51,75,81,85,125,135,153,225,243,255,257,289,
%T A174688 375,405,425,459,625,675,729,765,771,867,1125,1215,1275,1285,1377,
%U A174688 1445,1875,2025,2125,2187,2295,2313,2601,3125,3375,3645,3825,3855,4131,4335,4369
%N A174688 All different products of not necessarily distinct terms of A001317.
%C A174688 Sequence differs from A143512 beginning with a(970).
%H A174688 Amiram Eldar, <a href="/A174688/b174688.txt">Table of n, a(n) for n = 1..10000</a>
%F A174688 Sum_{n>=1} 1/a(n) = 2.
%F A174688 Let m_a(n) = (-1)^A010060(n), if n is squarefree, and 0, otherwise (a-analog of Möbius function). Then Sum_{n>=1} m_a(n)/a(n) = 1/2.
%F A174688 A generalization: Sum_{n>=1} 1/(a(n))^s = Product_{Fermat numbers F} (1-F^(-s))^(-1), where s>0 (an analog of Euler identity for primes, where, for real s, s>1).
%e A174688 9 = 3^2 is a term since 3 is in A001317.
%t A174688 f[n_] := FromDigits[Table[Mod[Binomial[n, k], 2], {k, 0, n}], 2]; n = 13; v = Array[f, n, 0]; vmax = v[[-1]]; s = {1}; Do[v1 = v[[k]]; rmax = Floor[Log[v1, vmax]]; s1 = v1^Range[0, rmax]; s2 = Select[Union[Flatten[Outer[Times, s, s1]]], # <= vmax &]; s = Union[s, s2], {k, 2, n}]; s (* _Amiram Eldar_, Sep 27 2020 *)
%Y A174688 Cf. A001317, A000215, A143512.
%K A174688 nonn
%O A174688 1,2
%A A174688 _Vladimir Shevelev_, Dec 01 2010
%E A174688 Offset corrected and more terms added by _Amiram Eldar_, Sep 27 2020