A117829 Start with 3 and repeatedly reverse the digits and add 4 to get the next term.

3, 7, 11, 15, 55, 59, 99, 103, 305, 507, 709, 911, 123, 325, 527, 729, 931, 143, 345, 547, 749, 951, 163, 365, 567, 769, 971, 183, 385, 587, 789, 991, 203, 306, 607, 710, 21, 16, 65, 60, 10, 5, 9, 13, 35, 57, 79, 101, 105, 505, 509, 909, 913, 323, 327, 727, 731, 141, 145

Offset: 1

Author

Luc Stevens (lms022(AT)yahoo.com), Apr 06 2006

Keywords

• nonn
• base

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000
• N. J. A. Sloane and others, Sequences of RADD type, OEIS wiki.
• Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).

Crossrefs

Cf. A117827, A117828, A117830.

Programs

Maple

read transforms; t1:=[3]; for n from 1 to 80 do t1:=[op(t1),4+digrev(t1[n])]; od: # N. J. A. Sloane

Mathematica

f[n_] := 4 + FromDigits@ Reverse@ IntegerDigits@n; NestList[ f@# &, 3, 58] (* James C. McMahon, Sep 24 2024 *)
NestList[IntegerReverse[#]+4&,3,60] (* Harvey P. Dale, Feb 17 2025 *)

Formula

Has period 54: see A117827, A117830.