# Summation this Summer! 3

Discrete Mathematics Level 4

$\dbinom{2n}{1}^2 +2.\dbinom{2n}{2}^2 +3.\dbinom{2n}{3}^2 \cdots \cdots + 2n.\dbinom{2n}{2n}^2$

Find the closed form of the above series.

Notation:
$$!$$ denotes the factorial notation. For example, $$8! = 1\times2\times3\times\cdots\times8$$.

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