A364921 Number of conjugacy classes of subgroups of the group GL(2, Z_n) of invertible 2 X 2 matrices mod n.

1, 4, 16, 62, 48, 109, 84, 2265, 324, 345, 114, 5359, 217, 636, 2540, 27908, 218, 2872, 272, 20933, 4089, 756, 169, 780487, 892, 1813, 3015, 30562, 349, 31419, 510, 191856, 5096, 1743, 14139, 115902, 685, 2156, 13191, 3764246, 662, 51063, 600, 38346, 56222, 1130, 271

Offset

1,2

Links

Table of n, a(n) for n=1..47.

Prog

(Magma) [#Subgroups(GL(2, ResidueClassRing(n))) : n in [2..50]];
(Sage) [len(GL(2, Zmod(n)).as_permutation_group().conjugacy_classes_subgroups()) for n in range(2, 50)]

Crossrefs

Cf. A000252, A066514.

Sequence in context: A283858 A283409 A192468 * A365835 A365860 A276042

Adjacent sequences: A364918 A364919 A364920 * A364922 A364923 A364924

Keyword

nonn

Author

Robin Visser, Aug 12 2023

Status

approved