A258700 Maximal index of a torsion-free congruence subgroup of PSL(2,Z) of genus n.

60, 108, 108, 168, 180, 192, 180, 216, 156, 288, 324, 240, 300, 384, 192, 288, 360, 480, 288, 504, 300, 480, 432, 384, 336

Offset

0,1

Links

Table of n, a(n) for n=0..24.

C. J. Cummins and S. Pauli, Congruence Subgroups of PSL(2,Z) of Genus Less than or Equal to 24, Experiment. Math. Volume 12, Issue 2 (2003), 243-255. See Table 1.

Crossrefs

A258691, A102474, A258693-A258700 give the ten sequences in Table 1 of Cummins and Pauli (2003).

Sequence in context: A043221 A039398 A044001 * A008887 A217738 A351548

Adjacent sequences: A258697 A258698 A258699 * A258701 A258702 A258703

Keyword

nonn,more

Author

N. J. A. Sloane, Jun 07 2015

Status

approved