Definition:Tribonacci Constant

Definition
The Tribonacci constant $\eta$ is the one real root of the cubic:
 * $x^3 - x^2 - x - 1 = 0$

Its decimal expansion starts:
 * $\eta = 1 \cdotp 83928 \, 67552 \, 1416 \ldots$

Also known as
Some sources leave its first letter in lowercase: tribonacci constant.