On a three-dimensional lattice, a random walk has less than unity probability of reaching any point (including the starting point) as the number of steps approaches infinity. The probability of reaching the starting point again is 0.3405373296.... This is one of Pólya's random walk constants.
Random Walk--3-Dimensional
See also
Pólya's Random Walk Constants, Random Walk--1-Dimensional, Random Walk--2-DimensionalExplore with Wolfram|Alpha
References
Glasser, M. L. and Zucker, I. J. "Extended Watson Integrals for the Cubic Lattices." Proc. Nat. Acad. Sci. U.S.A. 74, 1800-1801, 1977.McCrea, W. H. and Whipple, F. J. W. "Random Paths in Two and Three Dimensions." Proc. Roy. Soc. Edinburgh 60, 281-298, 1940.Trott, M. "The Mathematica Guidebooks Additional Material: Lattice Sites Visited by Random Walkers." http://www.mathematicaguidebooks.org/additions.shtml#S_2_04.Cite this as:
Weisstein, Eric W. "Random Walk--3-Dimensional." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/RandomWalk3-Dimensional.html