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 A167313 #12 Oct 21 2023 05:33:50
%S A167313 1,-3,0,9,6,0,12,-27,0,-18,24,0,30,-36,0,81,42,0,48,54,0,-72,60,0,36,
%T A167313 -90,0,108,78,0,84,-243,0,-126,72,0,102,-144,0,-162,114,0,120,216,0,
%U A167313 -180,132,0,144,-108,0,270,150,0,144,-324,0,-234,168,0,174,-252,0
%N A167313 Totally multiplicative sequence with a(p) = 3*(p-3) for prime p.
%H A167313 G. C. Greubel, <a href="/A167313/b167313.txt">Table of n, a(n) for n = 1..1000</a>
%F A167313 Multiplicative with a(p^e) = (3*(p-3))^e. If n = Product p(k)^e(k) then a(n) = Product (3*(p(k)-3))^e(k).
%F A167313 a(3k) = 0 for k >= 1.
%F A167313 a(n) = A165824(n) * A166589(n) = 3^bigomega(n) * A166589(n) = 3^A001222(n) * A166589(n).
%t A167313 a[1] = 1; a[n_] := (fi = FactorInteger[n]; Times @@ ((fi[[All, 1]] - 3)^fi[[All, 2]])); Table[a[n]*3^PrimeOmega[n], {n, 1, 100}] (* _G. C. Greubel_, Jun 08 2016 *)
%t A167313 f[p_, e_] := (3*(p-3))^e; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* _Amiram Eldar_, Oct 21 2023 *)
%Y A167313 Cf. A001222, A165824, A166589.
%K A167313 sign,easy,mult
%O A167313 1,2
%A A167313 _Jaroslav Krizek_, Nov 01 2009