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 A104194 #22 Nov 16 2024 02:58:52
%S A104194 0,0,0,0,0,0,0,2,0,0,0,2,0,0,4,4,0,0,0,4,6,0,0,6,0,0,0,6,0,4,0,8,10,0,
%T A104194 12,6,0,0,12,12,0,6,0,10,12,0,0,12,0,0,16,12,0,0,20,18,18,0,0,12,0,0,
%U A104194 30,16,36,10,0,16,22,12,0,18,0,0,20,18,30,12,0,28,0,0,0,18,48,0,28,30,0,12
%N A104194 a(n) = phi(n) - lambda(n).
%H A104194 Antti Karttunen, <a href="/A104194/b104194.txt">Table of n, a(n) for n = 1..10000</a>
%F A104194 a(n) = A000010(n) - A002322(n). - _Michel Marcus_, Mar 18 2016
%F A104194 a(n) = 0 if and only if n is in A033948. - _Amiram Eldar_, Nov 16 2024
%t A104194 Table[EulerPhi[n] - CarmichaelLambda[n], {n, 1, 200}]
%o A104194 (PARI) a(n) = eulerphi(n) - lcm(znstar(n)[2]); \\ _Michel Marcus_, Mar 18 2016
%Y A104194 Cf. A000010, A002322, A033948, A034380.
%K A104194 nonn
%O A104194 1,8
%A A104194 _Roger L. Bagula_, Mar 12 2005