Fransén–Robinson constant
From specialfunctionswiki
The Fransén–Robinson constant is defined to be the number $F$ given by the formula $$F = \displaystyle\int_0^{\infty} \dfrac{1}{\Gamma(x)} dx,$$ where $\dfrac{1}{\Gamma}$ denotes the reciprocal gamma function.
Properties
Relationship between the Fransén–Robinson constant, e, pi, and logarithm