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A119451 Let S_n be the infinite sequence formed by starting with n and repeatedly reversing the digits and adding 16 to get the next term. Sequence gives number of steps for S_n to reach a cycle, or -1 if no cycle is ever reached. 5
721, 708, 686, 709, 714, 656, 724, 756, 662, 721, 708, 695, 664, 732, 728, 715, 720, 707, 685, 708, 713, 655, 723, 755, 661, 15, 707, 712, 699, 686, 700, 732, 710, 0, 729, 1, 694, 654, 731, 709, 687, 710, 715, 657, 725, 757, 663, 722, 709, 714, 701, 688, 702 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

It is conjectured that S_n always reaches a cycle.

There is one cycle of length 54 (least component is 34, all components have at most four digits, cf. A119454), 19 different cycles of length 90 with 4-digit components (least components are 1027 + 2*k for k = 0, ..., 18, cf. A119455), 444 different cycles of length 450 with 6-digit components, 3 different cycles of length 810 with 6-digit components (least components are 101007, 101011, 101015), 19 different cycles of length 1890 with 6-digit components (least components are 100027 + 2*k for k = 0, ..., 18) and at least 19 different cycles of length 19890 with 8-digit components (least components are 10000027 + 2*k for k = 0, ..., 18).

LINKS

Table of n, a(n) for n=1..53.

N. J. A. Sloane and others, Sequences of RADD type, OEIS wiki.

CROSSREFS

S_1 is given in A118533. Records: A119452; where records occur: A119453. Cycles of length 54 and 90 are in A119454 and A119455.

Sequence in context: A283048 A282021 A186561 * A119452 A034179 A014440

Adjacent sequences:  A119448 A119449 A119450 * A119452 A119453 A119454

KEYWORD

nonn,base

AUTHOR

Klaus Brockhaus, May 20 2006

STATUS

approved

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Last modified November 14 12:40 EST 2019. Contains 329114 sequences. (Running on oeis4.)