Catalan's constant

English

Etymology

Named after French and Belgian mathematician Eugène Charles Catalan.

Proper noun

1. Template:Lb The number $G=\beta (2)=\sum _{n=0}^{\mathrm{\infty }}\frac{(-1{)}^n}{(2n+1{)}^2}=\frac{1}{1^2}-\frac{1}{3^2}+\frac{1}{5^2}-\frac{1}{7^2}+\frac{1}{9^2}-\cdots$, where Template:Math is the Dirichlet beta function, with a value of approximately 0.915965594177…