A258696 Total number of torsion-free congruence subgroups of PSL(2,Z) of genus n.

254, 459, 672, 1809, 1665, 3028, 1780, 6216, 2671, 6711, 4483, 8450, 4978, 12447, 4581, 16743, 8607, 17453, 4819, 24287, 9396, 27542, 11206, 22798, 6903

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: A144855 A110827 A062664 * A158249 A366553 A255178

Adjacent sequences: A258693 A258694 A258695 * A258697 A258698 A258699

Keyword

nonn,more

Author

N. J. A. Sloane, Jun 07 2015

Status

approved