RATS Sequence

A sequence produced by the instructions ``reverse, add, then sort the digits,'' where zeros are suppressed. For example, after 668 we get

$$668 + 866 = 1534,$$

so the next term is 1345. Applied to 1, the sequence gives 1, 2, 4, 8, 16, 77, 145, 668, 1345, 6677, 13444, 55778, ... (Sloane's A004000)

See also 196-Algorithm, Kaprekar Routine, Reversal, Sort-Then-Add Sequence

References

Sloane, N. J. A. Sequence A004000/M1137 in ``An On-Line Version of the Encyclopedia of Integer Sequences.'' http://www.research.att.com/~njas/sequences/eisonline.html and Sloane, N. J. A. and Plouffe, S. The Encyclopedia of Integer Sequences. San Diego: Academic Press, 1995.