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A258696 Total number of torsion-free congruence subgroups of PSL(2,Z) of genus n. 0
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 (list; graph; refs; listen; history; text; internal format)
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 A255178 A196738

Adjacent sequences:  A258693 A258694 A258695 * A258697 A258698 A258699

KEYWORD

nonn,more

AUTHOR

N. J. A. Sloane, Jun 07 2015

STATUS

approved

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Last modified January 23 12:31 EST 2021. Contains 340385 sequences. (Running on oeis4.)