Order of commutator subgroup of GL(2,Z_n) (invertible 2 X 2 matrices mod n: A000252).

Terms

a(0) =1a(1) =3a(2) =24a(3) =24a(4) =120a(5) =72a(6) =336a(7) =192a(8) =648a(9) =360a(10) =1320a(11) =576a(12) =2184a(13) =1008a(14) =2880a(15) =1536a(16) =4896a(17) =1944a(18) =6840a(19) =2880a(20) =8064a(21) =3960a(22) =12144a(23) =4608a(24) =15000a(25) =6552a(26) =17496a(27) =8064a(28) =24360a(29) =8640