Reverse-Then-Add Sequences
Reverse-Then-Add Sequences
Take a number, reverse its digits, and then add that to the original. This is called the "reverse-then-add" operation and repeatedly applying it to a number will produce its reverse-then-add sequence. For most numbers, the reverse-then-add operation quickly produces palindromes, which read the same backward or forward. The first number that is not known to eventually produce a palindrome is 196; thus, the reverse-then-add operation is sometimes known as the "196-algorithm."