# Triangles Are Important Here

$\large \dbinom{2n+1}3 = \dbinom{2n+2}n - \dbinom{2n+1}4$

Let $$a>1$$ and $$b>1$$ be the two solutions satisfying the equation above. What is the value of $$a+b$$?



Notation: $$\dbinom MN$$ denotes the binomial coefficient, $$\binom MN = \dfrac{M!}{N!(M-N)!}$$.

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