Minta tolong kak, makasih^^

A. U1=1 (1+1) (2+1) U2=2(2+1) (4+1)
=1.2.3 =2.3.5
=6 =30
U3=3 (3+1) (6+1)
=3.4.7
=84
B. U20=20 (20+1) (40+1)
=20.21.41
=17220