a(n) is the least integer k such that n/(Sum_{j=1..n} 1/phi(k*j)) is an integer.

Terms

a(0) =1a(1) =1a(2) =4a(3) =7a(4) =2a(5) =11a(6) =22a(7) =101a(8) =53a(9) =2a(10) =25a(11) =149a(12) =75a(13) =321a(14) =10a(15) =653a(16) =3110a(17) =907a(18) =5926a(19) =16829a(20) =2505a(21) =3174a(22) =13178a(23) =4323a(24) =5931a(25) =18033a(26) =20231a(27) =41698a(28) =155533a(29) =1323199