Reverse-Then-Add Sequence
The sequence obtained from reversing the digits of a number n and adding the result to the original number. For n=1, 2, ..., this gives 2, 4, 6, 8, 10, 12, 14, 16, 18, 11, 22, 33, 44, 55, 66, 77, 88, 99, 110, ... (OEIS A056964).
Looking at iterations of the reverse-then-add algorithm in base-2 gives the visualizations illustrated above, it which the left plot begins with 16 and runs 250 steps and the right plot begins with 512 and runs 500 steps (Wolfram 2002, pp. 125-127).
Applying the reverse-then-add operating iteratively until a palindromic number is obtained is called the 196-algorithm.
See also
196-Algorithm, Lychrel Number, RATS Sequence, Sort-Then-Add SequenceExplore with Wolfram|Alpha
More things to try:
References
Sloane, N. J. A. Sequence A056964 in "The On-Line Encyclopedia of Integer Sequences."Wolfram, S. A New Kind of Science. Champaign, IL: Wolfram Media, pp. 125-127, 2002.Referenced on Wolfram|Alpha
Reverse-Then-Add SequenceCite this as:
Weisstein, Eric W. "Reverse-Then-Add Sequence." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Reverse-Then-AddSequence.html