For real, Nonnegative terms and Real with , the expression
See also Continued Square Root
References
Herschfeld, A. ``On Infinite Radicals.'' Amer. Math. Monthly 42, 419-429, 1935.
Jones, D. J. ``Continued Powers and a Sufficient Condition for Their Convergence.'' Math. Mag. 68, 387-392, 1995.