Digamma at n+1/2

From specialfunctionswiki
Jump to: navigation, search

Theorem

The following formula holds for $n=1,2,3,\ldots$: $$\psi \left( n +\dfrac{1}{2} \right) = -\gamma - 2 \log(2)+ 2 \left( 1 + \dfrac{1}{3} + \ldots + \dfrac{1}{2n-1} \right),$$ where $\psi$ denotes the digamma function and $\gamma$ denotes the Euler-Mascheroni constant.

Proof

References