Reclaiming an index - Wiki Parity Tech Documentation

To reclaim an index I, you must be sure that I is currently mapped to a dead account (i.e. one with zero total balance). You need to craft a transaction that creates a new account by placing some balance B in it. B must satisfy these conditions:

B % 256 == 105

B / 256 % E == I

Where E is the quantized account index count:

E := (next_set_index * enum_set_size / 256 + 1) * 256

Given an amount to transfer A, you can calculate the lowest amount that is at least A, A' which will attempt to reclaim I as:

(Q(N / 256 + (E - 1 - I), E) + I) * 256 + N % 256

Where

N := Q(A + (256 - 1 - 105), 256) + 105