A316498 Number of normal subgroups of the special linear group SL(2, Z_n).

1, 3, 4, 7, 3, 13, 3, 15, 6, 10, 3, 32, 3, 10, 13, 26, 3, 20, 3, 25, 13, 10, 3, 75, 5, 10, 8, 25, 3, 48, 3, 37, 13, 10, 10, 50, 3, 10, 13, 60, 3, 48, 3, 25, 20, 10, 3, 135, 5, 17, 13, 25, 3, 27, 10, 60, 13, 10, 3, 127, 3, 10, 20, 48, 10, 48, 3, 25, 13, 38

Offset: 1

Author

Andrew Howroyd, Jul 04 2018

Keywords

• nonn

Crossrefs

Cf. A000056, A066541.

Programs

GAP

Concatenation([1], List([2..20], n->Size(NormalSubgroups(SL(2, Integers mod n)))));