A117841 Start with 1 and repeatedly reverse the digits and add 10 to get the next term.

1, 11, 21, 22, 32, 33, 43, 44, 54, 55, 65, 66, 76, 77, 87, 88, 98, 99, 109, 911, 129, 931, 149, 951, 169, 971, 189, 991, 209, 912, 229, 932, 249, 952, 269, 972, 289, 992, 309, 913, 329, 933, 349, 953, 369, 973, 389, 993, 409, 914, 429, 934, 449, 954, 469, 974, 489, 994, 509

Offset: 1

Author

David Applegate, May 05 2006

Keywords

• nonn
• base

Comments

This sequence (unlike A117828, say) never cycles.

The operation can never generate a trailing zero and so is reversible. So it loops only if it returns to the start, which is impossible. - Martin Fuller, May 12 2006

Links

• Harvey P. Dale and N. J. A. Sloane, Table of n, a(n) for n = 1..20000 (First 1000 terms from Harvey P. Dale)
• N. J. A. Sloane and others, Sequences of RADD type, OEIS wiki.

Crossrefs

Cf. A117830, A117828, A117816, A117817.

Programs

Mathematica

NestList[FromDigits[Reverse[IntegerDigits[#]]]+10&,1,60] (* Harvey P. Dale, May 19 2012 *)
NestList[IntegerReverse[#]+10&,1,60] (* Harvey P. Dale, May 29 2025 *)