# What kind of Binomial is this?

Algebra Level 4

$1 + \frac {2}{3} \left ( \frac 1 2 \right )^1 + \frac {2 \times 5}{3 \times 6} \left ( \frac 1 2 \right )^2 + \frac {2 \times 5 \times 8}{3 \times 6 \times 9} \left ( \frac 1 2 \right )^3 + \ldots$

If the series above can be stated in terms of form of $$a^{1/b}$$ for positive integers $$a,b$$, what is the value of $$a+b$$?

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