Catalan's Constant

The alternating sum of reciprocal odd squares, named for Eugène Catalan who studied its relations.

Specifications & Metrics

symbol

G

approx

0.91596559417721…

Core Principles & Analysis

• It first appeared in 1732, in a trigonometric series of Euler and Goldbach's correspondence.
• Whether G is irrational is open — like γ, it defies all known techniques.
• It measures the area under the Gaussian-like curve y = arctan x over one unit.