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 A167294 #13 Oct 19 2023 02:16:13 %S A167294 1,0,2,0,6,0,10,0,4,0,18,0,22,0,12,0,30,0,34,0,20,0,42,0,36,0,8,0,54, %T A167294 0,58,0,36,0,60,0,70,0,44,0,78,0,82,0,24,0,90,0,100,0,60,0,102,0,108, %U A167294 0,68,0,114,0,118,0,40,0,132,0,130,0,84,0,138,0,142,0 %N A167294 Totally multiplicative sequence with a(p) = 2*(p-2) for prime p. %H A167294 G. C. Greubel, <a href="/A167294/b167294.txt">Table of n, a(n) for n = 1..1000</a> %F A167294 Multiplicative with a(p^e) = (2*(p-2))^e. If n = Product p(k)^e(k) then a(n) = Product (2*(p(k)-2))^e(k). %F A167294 a(2k) = 0 for k >= 1. %F A167294 a(n) = A061142(n) * A166586(n) = 2^bigomega(n) * A166586(n) = 2^A001222(n) * A166586(n). %t A167294 a[1] = 1; a[n_] := (fi = FactorInteger[n]; Times @@ ((fi[[All, 1]] - 2)^fi[[All, 2]])); Table[a[n]*2^PrimeOmega[n], {n, 1, 100}] (* _G. C. Greubel_, Jun 06 2016 *) %t A167294 f[p_, e_] := (2*(p-2))^e; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* _Amiram Eldar_, Oct 19 2023 *) %Y A167294 Cf. A001222, A061142, A166586. %K A167294 nonn,easy,mult %O A167294 1,3 %A A167294 _Jaroslav Krizek_, Nov 01 2009