[seqfan] Essicran Numbers

Eric Angelini Eric.Angelini at kntv.be
Tue Oct 27 00:54:40 CET 2015

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:

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".


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