This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A084364 #15 Dec 14 2023 05:12:08 %S A084364 19,28,37,46,55,64,73,82,91,19,28,37,46,55,64,73,82,91,19,28,37,46,55, %T A084364 64,73,82,91,19,28,37,46,55,64,73,82,91,19,28,37,46,55,64,73,82,91,19, %U A084364 28,37,46,55,64,73,82,91,19,28,37,46,55,64,73,82,91,19,28,37,46,55,64 %N A084364 Define the operations M: multiply by 11, D: divide by 11, R: reverse digits. Sequence gives trajectory of 19 under action of M,R,D,R. %C A084364 Every such sequence is periodic. Sequences for a(1) = 1 to 18 are cyclic with a period of 1. %e A084364 19 -> 209 -> 902 -> 82 -> 28. %t A084364 mrdr[n_]:=FromDigits[Reverse[IntegerDigits[FromDigits[ Reverse[ IntegerDigits[ 11n]]]/ 11]]]; NestList[mrdr,19,70] (* _Harvey P. Dale_, Oct 01 2015 *) %K A084364 base,easy,nonn %O A084364 0,1 %A A084364 _Amarnath Murthy_, May 27 2003 %E A084364 Edited by _Patrick De Geest_ and _N. J. A. Sloane_, Jun 03 2003