A077404 Trajectory of n under the Reverse and Add! operation carried out in base 3 (presumably) does not reach a palindrome.

103, 127, 167, 176, 180, 183, 185, 191, 197, 200, 206, 207, 209, 215, 221, 230, 239, 291, 309, 318, 340, 358, 369, 376, 387, 394, 396, 413, 418, 431, 436, 449, 454, 467, 472, 582, 600, 618, 636, 655, 660, 673, 678, 691, 696, 709, 714, 746, 776, 803, 805

Offset: 1

Author

Klaus Brockhaus, Nov 05 2002

Keywords

• base
• nonn

Comments

Base-3 analog of A066059 (base 2), A075420 (base 4) and A023108 (base 10).

Links

• A.H.M. Smeets, Table of n, a(n) for n = 1..20000
• Index entries for sequences related to Reverse and Add!

Crossrefs

Cf. A023108, A066059, A075420, A077405.

Programs

ARIBAS

m := 900; stop := 1000; for n := 0 to m do c := 0; k := n; b := 1; while b do d := k; rev := 0; while d > 0 do rev := 3*rev + (d mod 3); d := d div 3; end; if k = rev or c = stop then b := 0; else k := k + rev; end; inc(c); end; if c > stop then write(n,","); end; end;

Mathematica

limit = 10^3; (* Assumes that there is no palindrome if none is found before "limit" iterations *)
Select[Range[805],
 Length@NestWhileList[# + IntegerReverse[#, 3] &, #, # !=
IntegerReverse[#, 3]  &, 1, limit] == limit + 1 &] (* Robert Price, Oct 19 2019 *)

Extensions

Offset changed to 1 by A.H.M. Smeets, Feb 10 2019