Numbers k such that normalizer of Gamma_0(k) is triangle group (2,4,inf).
A018229
Numbers k such that normalizer of Gamma_0(k) is triangle group (2,4,inf).
Terms
- a(0) =2a(1) =8a(2) =18a(3) =32a(4) =72a(5) =128a(6) =288a(7) =1152
External references
- oeis: A018229