public int[] getRedundancyArray(int redundancy) {
            if (redundancy == 0 || redundancy >= preCalculatedResults.length) {
                throw new IllegalArgumentException("Can only retrieve redundancy arrays in the inclusive range 1-" + (preCalculatedResults.length - 1) + ".");
            }
            return preCalculatedResults[redundancy];
        }
The distribution class keeps precalculated arrays for distributions for all legal redundancies. The class is
immutable, such that it can be returned safely out from the group object. (Actually, it's not immutable.)
vdslib/src/main/java/com/yahoo/vdslib/distribution/Group.java