SOLUTION: Write an algebraic expression for the following sequence 2, 4, 8, 14, 22, 32, ....

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Question 392911: Write an algebraic expression for the following sequence 2, 4, 8, 14, 22, 32, ....
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
The recursion formula is a(n) = a(n-1) + 2*(n-1) = a(n-2) + 2*(n-2) + 2*(n-1) = a(n-3) + 2*(n-3) + 2*(n-2) + 2*(n-1) = ... = a(1) + 2*1 + 2*2 + ... + 2*(n-2) + 2*(n-1) = 2 + 2(1 + 2 + ..+ (n-2) + (n - 1)) = 2 + (n - 1)n = n%5E2+-+n+%2B+2.
Therefore +a%28n%29+=+n%5E2-+n+%2B+2.