a(n) is the smallest number such that gcd(a(n), sigma(a(n))) = n.

Terms

a(0) =1a(1) =10a(2) =15a(3) =12a(4) =95a(5) =6a(6) =91a(7) =56a(8) =153a(9) =40a(10) =473a(11) =24a(12) =117a(13) =182a(14) =135a(15) =336a(16) =1139a(17) =90a(18) =703a(19) =380a(20) =861a(21) =946a(22) =3151a(23) =168a(24) =3725a(25) =468a(26) =1431a(27) =28a(28) =5017a(29) =570