a(1) = 1; a(n) = a(n-1)-th nontotient number.

Terms

a(0) =1a(1) =14a(2) =114a(3) =594a(4) =2532a(5) =9658a(6) =34066a(7) =113930a(8) =366358a(9) =1141614a(10) =3465398a(11) =10291022a(12) =29988178a(13) =85961454a(14) =242870564a(15) =677436550a(16) =1867877934