Numbers k such that normalizer of Gamma_0(k) is triangle group (2,6,inf).
A018230
Numbers k such that normalizer of Gamma_0(k) is triangle group (2,6,inf).
Terms
- a(0) =3a(1) =12a(2) =27a(3) =48a(4) =108a(5) =192a(6) =432a(7) =1728
External references
- oeis: A018230