[seqfan] Re: Revenant numbers

[Neil Sloane]

Eric, Very nice!  It is now A328095.
Best regards
Neil

Neil J. A. Sloane, President, OEIS Foundation.
11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
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On Sat, Oct 19, 2019 at 12:51 PM Éric Angelini <bk263401 at skynet.be> wrote:

> Hello SeqFans (cross-posted on Math-Fun),
> Take an integer abc...z and multiply it by all its digits: if the string
> abc...z appears in the result, we have a "revenant number".
>
> Look at 87 for instance: 87 * 8 * 7 = 4872. As the string 87 is visible in
> the result, 87 is a revenant.
> So is 792 because 792 * 7 * 9 * 2 = 99792.
> And 9375 as 9375 * 9 * 3 * 7 * 5 = 8859375.
>
> If we start a sequence R of revenants we'll get (not in the OEIS):
>
> R = 0, 1, 5, 6, 11, 25, 52, 77, 87, 111, 125, 152, 215, 251, 375, 376,
> 455, 512, 521, 545, 554, 736, 792, 1111, 1125, 1152, 1215, 1251, 1455,
> 1512, 1521, 1545, 1554, 2115, 2151, 2174, 2255, 2511, 2525, 2552, 4155,
> 4515, 4551, 5112, 5121, 5145, 5154, 5211, 5225, 5252, 5415, 5451, 5514,
> 5522, 5541, 5558, 5585, 5855, 8555, 8772, 9375,...
>
> R is infinite, of course, as all repunits (like 11, 111, 1111, 1111,...)
> will be in R.
>
> Will you find the next revenant > 62227496 whose "image" doesn't show any
> zero?
>
> More details, DiCaprio and a graph here:
> http://cinquantesignes.blogspot.com/2019/10/revenant-numbers.html
>
> Best,
> É.
>
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