Binomial Theorem and Its Simple Applications: JEE Main 2021 Mathematics question

Let n$\in$N and [x] denote the greatest integer less than or equal to x. If the sum of (n + 1) terms ${}^n{C_0},3.{}^n{C_1},5.{}^n{C_2},7.{}^n{C_3},.....$ is equal to 2¹⁰⁰ . 101, then $2\left[ {{{n - 1} \over 2}} \right]$ is equal to _______________.