MathCastle
CalculusSuperchallengeInfinite Sequences and Series

Infinite Sequences and Series · Superchallenge problem

Find the exact value of ∑n=0∞(2nn)18n=1+28+664+20512+⋯\displaystyle\sum_{n=0}^{\infty}\binom{2n}{n}\frac{1}{8^n}=1+\frac{2}{8}+\frac{6}{64}+\frac{20}{512}+\cdots.