%I #4 Mar 30 2012 18:50:29

%S 1,4,10,40,100,40,72,400,720,400,672,400,732,288,1000,4000,9792,2880,

%T 6440,4000,5184,2688,10110,4000,6912,2928,7920,2880,10432,4000,10800,

%U 40000,90900,39168,59904,28800,65520,25760,86040,40000,66560,20736

%N Euler's totient of numbers containing in their decimal representation only the digits 0 and 1.

%F a(n) = A000010(A007088(n)).

%e a(20) = A000010(A007088(20)) = A000010(10100) = A000010(2*2*5*5*101) = 10100*(1-1/2)*(1-1/5)*(1-1/101) = 4000.

%K nonn,base

%O 1,2

%A _Reinhard Zumkeller_, Nov 16 2002