a(n) = smallest k such that phi(n+k) = phi(k).

Terms

a(0) =1a(1) =4a(2) =3a(3) =8a(4) =5a(5) =24a(6) =5a(7) =13a(8) =9a(9) =20a(10) =7a(11) =48a(12) =13a(13) =16a(14) =13a(15) =26a(16) =17a(17) =52a(18) =19a(19) =37a(20) =21a(21) =44a(22) =13a(23) =96a(24) =25a(25) =34a(26) =27a(27) =32a(28) =13a(29) =124