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A118522 Define sequence S_n by: initial term = n, reverse digits and add 3 to get next term. It is conjectured that S_n always reaches a cycle. Sequence gives number of steps for S_n to reach a cycle. 3

%I #12 Jan 16 2018 03:16:00

%S 1,3,3,0,2,2,0,1,1,0,0,0,6,0,0,0,4,0,0,3,0,0,14,0,0,0,4,0,0,3,0,0,11,

%T 5,13,10,3,6,6,1,5,5,4,0,0,4,0,0,0,2,0,0,7,0,0,12,0,0,0,2,0,0,7,0,0,9,

%U 3,11,8,1,4,4,2,3,3,2,0,0,2,0,0,0,6,0,0,5,0,0,10,0,0,0,6,0,0

%N Define sequence S_n by: initial term = n, reverse digits and add 3 to get next term. It is conjectured that S_n always reaches a cycle. Sequence gives number of steps for S_n to reach a cycle.

%C Initial cycles have length 3 or 6.

%C From _Lars Blomberg_, Jan 15 2018: (Start)

%C For n < 10^8, the only cycles found are the following:

%C [4,7,10]

%C [18,84,51]

%C [29,95,62]

%C [11,14,44,47,77,80]

%C [12,24,45,57,78,90]

%C [15,54,48,87,81,21]

%C [16,64,49,97,82,31]

%C [19,94,52,28,85,61]

%C [22,25,55,58,88,91]

%C [26,65,59,98,92,32]

%C The union of all of them has 51 terms (= 3*3 + 7*6): [4, 7, 10, 11, 12, 14, 15, 16, 18, 19, 21, 22, 24, 25, 26, 28, 29, 31, 32, 44, 45, 47, 48, 49, 51, 52, 54, 55, 57, 58, 59, 61, 62, 64, 65, 77, 78, 80, 81, 82, 84, 85, 87, 88, 90, 91, 92, 94, 95, 97, 98] (End)

%H Lars Blomberg, <a href="/A118522/b118522.txt">Table of n, a(n) for n = 1..10000</a>

%H N. J. A. Sloane and others, <a href="/wiki/Sequences_of_RADD_type">Sequences of RADD type</a>, OEIS wiki.

%Y For records see A118523, A118524. Cf. A117831. For S_1, S_2 etc. see A118517-A118521.

%K nonn,base

%O 1,2

%A _N. J. A. Sloane_, May 06 2006

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