[seqfan] Re: Interesting discovery by Dan Preston concerning a Recaman-like sequence

[M. F. Hasler]

FWIW, I have included (very simple) C++ code which deals even with large
values like a(30) = 8869123
and a(11284) = 19675891  in a few seconds.
For n = 11281 it seems that indeed some more thinking is needed.
I must express my admiration to the inventor of such an extremely simple
and nontrivial sequence.
-- 
Maximilian

On Mon, Mar 18, 2019 at 8:07 AM <hv at crypt.org> wrote:

> I have some ideas about for algorithms to cope with the difficult cases,
> which I'm just starting to implement.
>
> Hugo
>

On Mon, Mar 18, 2019 Neil Sloane  wrote:

> Dan Preston just wrote to me about an interesting discovery he has made.

The Recaman-variant A228474 seems to have an extraordinary jump at n=11281

(or, less likely, it doesn't converge there)

He finds the following values:


> WreckerBall[11276] = 632100

WreckerBall[11277] = 632102

WreckerBall[11278] = 632104

WreckerBall[11279] = 632106

WreckerBall[11280] = 631064

WreckerBall[11281] still calculating after 32,200,000,000 steps...

//Segmentation fault: 11

WreckerBall[11282] = 631072

WreckerBall[11283] = 631070

WreckerBall[11284] = 19675891

WreckerBall[11285] = 631078

WreckerBall[11286] = 631076