\begin{definition}[Definition:Lychrel Number/Candidate]
No natural number has been '''proved''' to be a '''Lychrel number''' as of time of writing (June $2017$).  However, plenty of numbers have not shown themselves to terminate in a palindromic number, although in some cases millions of iterations have been tested.
Hence a '''candidate Lychrel number''' is a natural number which '''is not known to''' form a palindromic number through repeated iteration of the reverse-and add process.
\end{definition}