Largest number which requires n iterations of the bi-unitary totient function (A116550) to reach 1.

Terms

a(0) =1a(1) =2a(2) =3a(3) =6a(4) =10a(5) =11a(6) =12a(7) =18a(8) =30a(9) =42a(10) =78a(11) =106a(12) =210a(13) =366a(14) =550a(15) =603a(16) =750a(17) =1290a(18) =2562a(19) =4398a(20) =4305a(21) =7470a(22) =9090a(23) =14322a(24) =24558a(25) =35382a(26) =55482a(27) =78020a(28) =141190a(29) =207519