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 A165872 #23 Jun 04 2023 12:07:55
%S A165872 1,-2,-2,4,-2,4,-2,-8,4,4,-2,-8,-2,4,4,16,-2,-8,-2,-8,4,4,-2,16,4,4,
%T A165872 -8,-8,-2,-8,-2,-32,4,4,4,16,-2,4,4,16,-2,-8,-2,-8,-8,4,-2,-32,4,-8,4,
%U A165872 -8,-2,16,4,16,4,4,-2,16,-2,4,-8,64,4,-8,-2,-8,4,-8,-2,-32,-2,4,-8,-8,4,-8,-2,-32,16,4,-2,16,4,4,4,16
%N A165872 Totally multiplicative sequence with a(p^e) = (-2)^e.
%C A165872 The Dirichlet series is Product_{prime p} 1/(1+2/p^s), related to the Feller-Tornier constants like A065474. - _R. J. Mathar_, Feb 07 2011
%H A165872 G. C. Greubel, <a href="/A165872/b165872.txt">Table of n, a(n) for n = 1..10000</a>
%F A165872 a(n) = A122803(A001222(n)) = (-2)^bigomega(n) = (-2)^A001222(n).
%F A165872 Abs(a(n)) = A061142(n).
%t A165872 (-2)^PrimeOmega[Range[100]] (* _G. C. Greubel_, Apr 16 2016 *)
%o A165872 (PARI) a(n) = (-2)^bigomega(n); \\ _Altug Alkan_, Apr 16 2016
%Y A165872 Cf. A001222, A061142, A065474, A122803.
%K A165872 sign,mult
%O A165872 1,2
%A A165872 _Jaroslav Krizek_, Sep 28 2009