a(0)=2. a(n) = the a(n-1)th integer from among those positive integers coprime to n.

Terms

a(0) =2a(1) =2a(2) =3a(3) =4a(4) =7a(5) =8a(6) =23a(7) =26a(8) =51a(9) =76a(10) =189a(11) =207a(12) =619a(13) =670a(14) =1563a(15) =2929a(16) =5857a(17) =6223a(18) =18667a(19) =19704a(20) =49259a(21) =86203a(22) =189645a(23) =198265a(24) =594793a(25) =743491a(26) =1610897a(27) =2416345a(28) =5638137a(29) =5839499