A065501 Number of conjugacy classes in the group SL(2,Z_n) (see A000056).

1, 3, 7, 10, 9, 21, 11, 30, 25, 27, 15, 70, 17, 33, 63, 76, 21, 75, 23, 90, 77, 45, 27, 210, 49, 51, 79, 110, 33, 189, 35, 168, 105, 63, 99, 250, 41, 69, 119, 270, 45, 231, 47, 150, 225, 81, 51, 532, 81, 147, 147, 170, 57, 237, 135, 330, 161, 99, 63, 630, 65, 105, 275, 352, 153

Offset: 1

Author

Dan Fux (dan.fux(AT)OpenGaia.com or danfux(AT)OpenGaia.com), Nov 25 2001

Keywords

• nonn
• mult

Links

• Robin Visser, Table of n, a(n) for n = 1..500

Crossrefs

Cf. A062354, A000056, A000252

Programs

Magma

[Nclasses(SpecialLinearGroup(2,ResidueClassRing(n))) : n in [2..50]]; // Robin Visser, Aug 06 2023

Formula

For an odd prime p : a(p) = p + 4. - Robin Visser, Aug 06 2023

Extensions

a(23) corrected and more terms from Robin Visser, Aug 06 2023