Numbers k such that normalizer of Gamma_0(k) is a triangle group.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =8a(5) =9a(6) =12a(7) =16a(8) =18a(9) =27a(10) =32a(11) =36a(12) =48a(13) =64a(14) =72a(15) =108a(16) =128a(17) =144a(18) =192a(19) =256a(20) =288a(21) =432a(22) =576a(23) =1152a(24) =1728a(25) =2304