Files of the form n.rad contain information on palindromes in the versum
sequence for n for radices 2 through 60.

The top row labels the radices; 2 through 9 are radices in base 10.  The
next 52 radices are labeled by &letters.

Note that the first term in n.rad is n + reverse(n); thus the first term
for 9.rad is 18.