\begin{thebibliography}{1}

\bibitem{MR3056627}
B.~Chaffin, J.~P. Linderman, N.~J.~A. Sloane, and A.~R. Wilks, On curling
  numbers of integer sequences, {\em J. Integer Seq.} {\bf \textbf{16}} (2013),
  \href{https://cs.uwaterloo.ca/journals/JIS/VOL16/Sloane/sloane3.html}{Article
  13.4.3}.

\bibitem{oeis}
The OEIS~Foundation Inc., The {On-Line} {Encyclopedia} of {Integer}
  {Sequences}, Published electronically at \url{http://oeis.org}.

\bibitem{MR2268453}
F.~J. van~de Bult, D.~C. Gijswijt, J.~P. Linderman, N.~J.~A. Sloane, and A.~R.
  Wilks, A slow-growing sequence defined by an unusual recurrence, {\em J.
  Integer Seq.} {\bf \textbf{10}} (2007),
  \href{https://cs.uwaterloo.ca/journals/JIS/VOL10/Sloane/sloane55.html}{Article
  07.1.2}.

\end{thebibliography}
