[seqfan] Re: Essicran Numbers

Reinhard Zumkeller reinhard.zumkeller at gmail.com
Tue Oct 27 09:32:03 CET 2015


see https://oeis.org/A263808
:-)  Reinhard



2015-10-27 0:54 GMT+01:00 Eric Angelini <Eric.Angelini at kntv.be>:

> Hello SeqFans,
>
> An Essicran integer X turns into -X
> after a few subtractions.
>
> If you iterate 2015-2-0-1-5-2-0-1-5-2-0-1-5-2-0-1-5-2... long enough
> and reach at some stage -2015, then
> you have a "hit"... and an Essicran number.
>
> 1 is (of course) a EN
> 2 is a EN
> 3 is a EN, as are 4,5,5,7,8,9,10,11;
> 12 is a EN
> 13 is not because the successive
> subtractions -1 and -3 never hit
> -13 at some point hereunder:
>
> 13-1=12-3=9-1=8-3=5-1=4-3=1-1=0
> 0-3=-3-1=-4-3=-7-1=-8-3=-11-1=-12-3=-15... miss!
>
> "Narcissic" (or Armstrong) numbers
> already exist in the OEIS -- this is
>  why I've coined "Essicran".
>
> Best,
> É.
>
>
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