MathCastle
Counting & ProbabilityMediumRecursion, Catalan Numbers & Generating Functions

Recursion, Catalan Numbers & Generating Functions · Medium problem

Using Cn+1=2(2n+1)n+2 CnC_{n+1}=\dfrac{2(2n+1)}{n+2}\,C_n and C6=132C_6=132, compute C7C_7.