%I #12 Dec 21 2016 02:42:23

%S 1,2,2,4,2,3,3,4,6,4,3,6,4,4,4,8,4,8,4,6,5,6,4,5,8,6,5,8,4,8,5,9,5,6,

%T 5,12,6,5,8,8,6,6,6,8,8,8,5,12,9,12,8,8,6,6,8,6,6,8,5,10,8,6,10,12,8,

%U 10,6,9,6,10,8,12,9,9,12,10,6,10,6,12,8,9,8,12,9,8

%N a(n) = tau(phi(sigma(n)))

%H G. C. Greubel, <a href="/A163371/b163371.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = A000005(A000010(A000203(n))) = A000005(A062401(n)) = A062821(A000203(n)).

%p with(numtheory): A163371:=n->tau(phi(sigma(n))): seq(A163371(n), n=1..150); # _Wesley Ivan Hurt_, Dec 19 2016

%t DivisorSigma[0, EulerPhi[DivisorSigma[1, Range[100]]]] (* _G. C. Greubel_, Dec 19 2016 *)

%o (PARI) vector(50, n, numdiv(eulerphi(sigma(n)))) \\ _G. C. Greubel_, Dec 19 2016

%Y Cf. A000005, A000010, A000203, A062401, A062821.

%K nonn,easy

%O 1,2

%A _Jaroslav Krizek_, Jul 25 2009