a(0)=1; a(n) = Sum_{j<n, gcd(n,a(j)) = 1} a(j).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =2a(5) =10a(6) =2a(7) =22a(8) =2a(9) =46a(10) =2a(11) =72a(12) =2a(13) =168a(14) =2a(15) =88a(16) =2a(17) =428a(18) =2a(19) =858a(20) =2a(21) =620a(22) =2a(23) =2294a(24) =2a(25) =4006a(26) =2a(27) =7546a(28) =2a(29) =16192