At these values of k the first, 2nd and 3rd cyclotomic polynomials all give prime numbers.

Terms

a(0) =6a(1) =12a(2) =138a(3) =150a(4) =192a(5) =348a(6) =642a(7) =1020a(8) =1092a(9) =1230a(10) =1620a(11) =1788a(12) =1932a(13) =2112a(14) =2142a(15) =2238a(16) =2658a(17) =2688a(18) =2730a(19) =3330a(20) =3540a(21) =3918a(22) =4002a(23) =4158a(24) =5010a(25) =5640a(26) =6090a(27) =6450a(28) =6552a(29) =6702