Find the `8^(th)` term of the sequence whose first three terms are 3, 3, 6 and each term after the second is the sum of the two terms preseding it .

Explanation

Let `a_(n) ` be the `n^(th)` term of the sequence .
`a_(1)= 3. a_(2) = 3. a_(3) = 6`
and `a_(n) = a_(n-1) + a_(n -2). N gt 2`
`therefore a_(3) = a_(2) + a_(1) = 3 + 3 = 6 `
`a_(4) = a_(3) + a_(2) = 6 + 3 = 9 `
`a_(5) = a_(4) + a_(3) = 9 + 6 = 15`
`a_(6) = a_(5) + a_(4) = 15 + 9 = 24 `
`a_(7) = a_(6) + a_(5) = 24 + 15 = 39 `
`a_(8) = a_(7) + a_(6) = 39 + 24 = 63 `
`therefore 8^(th)` term of the sequence = 63