A033670 Trajectory of 89 under map x->x + (x-with-digits-reversed).

89, 187, 968, 1837, 9218, 17347, 91718, 173437, 907808, 1716517, 8872688, 17735476, 85189247, 159487405, 664272356, 1317544822, 3602001953, 7193004016, 13297007933, 47267087164, 93445163438

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• base

Comments

The sequence reaches a palindrome at a(24)= 8813200023188 (cf. A033665). - Klaus Brockhaus, Jun 07 2002

Examples

			a(3) = 968 because 187 + 781 = 968
		

References

• Popular Computing (Calabasas, CA), The 196 Problem, Vol. 3 (No. 30, Sep 1975), page PC30-6. Gives full 25-term trajectory of 89.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Jason Doucette, World Records
• I. Peter, More trajectories
• Index entries for sequences related to Reverse and Add!

Programs

Mathematica

NestList[# + FromDigits[Reverse[IntegerDigits[#]]]&, 89, 40] (* Vincenzo Librandi, May 03 2014 *)