Find the sum to n terms of the series:

1 . 2 . 4 + 2. 3 . 7 + 3. 4. 10 +..............

Let T_n be the nth terms of the series
       T_n = [nth terms of 1, 2, 3, .......]  [ nth terms of 2, 3, 4, ......]  [nth term of 4, 7, 10, ........]
 
          = [ 1 + (n -1) 1] [2 + (n - 1)1] [4 + (n - 1)3]
          = (1 + n - 1) (2 + n - 1) (4 + 3n - 3) = n(n + 1) (3n + 1)
     T_n  = 3n³ + 4n² + n
Let   S_n denote the sum of n terms of the series:
 ∴   

                       
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