Compute 12 + (12 + 11) + (12 + 11 + 10) + ... + (12 + 11 + 10 + ... + 1).
Sum[12, 23, 33, 42, 50, 57, 63, 68, 72, 75, 77, 78] =650
12*12 + 11* 11 + 10 *10 + 9*9......+1=
12^2 + 11^2 +10 ^2 .....
144 + 121 + 100 + 81 + 64 + 49 + 36 + 25 + 16 + 9 + 4 + 1 = 650
+36916 
