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| A228474
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Number of steps required to reach zero in the wrecker ball sequence starting with n: On the k-th step (k = 1, 2, 3, ...) move a distance of k in the direction of zero. If the result has occurred before, move a distance of k away from zero instead. Set a(n) = -1 if 0 is never reached.
(history;
published version)
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#105 by Charles R Greathouse IV at Thu May 16 01:32:32 EDT 2019
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Gordon Hamilton, <a href="http://www.youtube.com/watch?v=mQdNaofLqVc&feature=youtu.be">Wrecker Ball Sequences</a>, Video, 2013. [The sequence is mentioned about 4.5 minutes in to the video. The video begins by discussing A005132. - N. J. A. Sloane, Apr 25 2019]
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Discussion
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| Thu May 16
| 01:32
| OEIS Server: https://oeis.org/edit/global/2815
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#104 by N. J. A. Sloane at Thu Apr 25 10:10:46 EDT 2019
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#103 by N. J. A. Sloane at Thu Apr 25 10:10:43 EDT 2019
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Gordon Hamilton, <a href="http://www.youtube.com/watch?v=mQdNaofLqVc&feature=youtu.be">Wrecker Ball Sequences</a>, Video, 2013. [The sequence is mentioned about 4.5 minutes in to the video. The video begins by discussing A005132. - _N. J. A. Sloane_, Apr 25 2019]
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approved
editing
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#102 by Peter Luschny at Tue Apr 09 10:19:11 EDT 2019
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#101 by Hans Havermann at Tue Apr 09 08:45:32 EDT 2019
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Discussion
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| Tue Apr 09
| 10:19
| Peter Luschny: I agree.
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#100 by Hans Havermann at Tue Apr 09 08:36:12 EDT 2019
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(Is it proved or only conjectured?)
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Hans Havermann, <a href="http://gladhoboexpress.blogspot.com/2019/04/sharp-peaks-and-high-plateaus.html">Sharp peaks and high plateaus</a> An overview of large knowns and unknowns up to index 10^6.
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proposed
editing
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Discussion
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| Tue Apr 09
| 08:42
| Hans Havermann: I've removed Daniel's comment. Altering an existing comment does seem to be an intrusive way to ask a question. That's why we have the Sequence Fanatics Discussion list.
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#99 by Hans Havermann at Sun Apr 07 10:43:20 EDT 2019
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Discussion
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| Mon Apr 08
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| Michael B. Porter: If m is the n-th triangular number m = 1+2+...+n, then doesn't the wrecker ball sequence go m, m-1, m-1-2, ..., m-1-2-...-k = 0? So there are n steps to reach 0.
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#98 by Hans Havermann at Sun Apr 07 10:28:57 EDT 2019
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Hans Havermann, <a href="http://gladhoboexpress.blogspot.com/2019/04/sharp-peaks-and-high-plateaus.html">Sharp peaks and high plateaus</a> overview of large unknowns up to index 10^6
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proposed
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Discussion
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| Sun Apr 07
| 10:39
| Hans Havermann: Daniel, if your "is it proved or only conjectured" refers to Neil's added escape clause, my take is that it will always be an open question, but only because we do not have the ability or time to resolve large finite results. Like a random one-dimensional walk, I see no reason why values should escape to infinity.
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| 10:43
| Hans Havermann: Oops, sorry Daniel. I see now where you placed your comment. So I take my answer back, if only I could.
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#97 by Daniel Forgues at Mon Apr 01 21:11:26 EDT 2019
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#96 by Daniel Forgues at Mon Apr 01 21:04:47 EDT 2019
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(Is it proved or only conjectured?)
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approved
editing
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Discussion
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| Mon Apr 01
| 21:11
| Daniel Forgues: Since I can only add pink box comments after I save an edit, I had to first save my comment as an edit. It would be convenient to be able to do a pink box comment without the need to do an edit.
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