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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. 1

%I

%S 19,28,37,46,55,64,73,82,91,19,28,37,46,55,64,73,82,91,19,28,37,46,55,

%T 64,73,82,91,19,28,37,46,55,64,73,82,91,19,28,37,46,55,64,73,82,91,19,

%U 28,37,46,55,64,73,82,91,19,28,37,46,55,64,73,82,91,19,28,37,46,55,64

%N 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 Every such sequence is periodic. Sequences for a(1) = 1 to 18 are cyclic with a period of 1.

%F a(n)=(19/36)*{343/19*[n mod 9]+[(n+1) mod 9]+[(n+2) mod 9]+[(n+3) mod 9]+[(n+4) mod 9]+[(n+5) mod 9]+[(n+6) mod 9]+[(n+7) mod 9]+[(n+8) mod 9]}, with n>=0 - _Paolo P. Lava_, Jun 08 2007

%e 19 -> 209 -> 902 -> 82 -> 28.

%t mrdr[n_]:=FromDigits[Reverse[IntegerDigits[FromDigits[ Reverse[ IntegerDigits[ 11n]]]/ 11]]]; NestList[mrdr,19,70] (* _Harvey P. Dale_, Oct 01 2015 *)

%K base,easy,nonn

%O 0,1

%A _Amarnath Murthy_, May 27 2003

%E Edited by _Patrick De Geest_ and _N. J. A. Sloane_, Jun 03 2003

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Last modified July 23 19:17 EDT 2021. Contains 346259 sequences. (Running on oeis4.)