a(n) = Sum_{j=1..n} phi(n)^j.

Terms

a(0) =1a(1) =2a(2) =14a(3) =30a(4) =1364a(5) =126a(6) =335922a(7) =87380a(8) =12093234a(9) =1398100a(10) =111111111110a(11) =22369620a(13) =94036996914