[seqfan] Re: Smallest prime wich is equal to a multiple of his reversal +/- a prime smaller than him in n ways

Claudio Meller claudiomeller at gmail.com
Mon Dec 12 00:44:15 CET 2011


Olivier:
Yes, 71 has three solutions, thanks

2011/12/11 Olivier Gerard <olivier.gerard at gmail.com>

> Mr Meller,
>
> If I understand well the constraints you define,
> you missed 71 ,401 and 521 among others which have all 3 solutions in base
> 10.
>
> Example:
>
> 71 = 4*17+3 = 2*17+37 = 6*17-31
>
> Regards,
>
> Olivier
>
>
> On Sun, Dec 11, 2011 at 22:59, Claudio Meller <claudiomeller at gmail.com
> >wrote:
>
> > Hi seqfans:
> >
> > In
> >
> >
> http://simplementenumeros.blogspot.com/2011/12/833-igual-un-multiplo-del-inverso-mas.html
> >  I put this problem :
> >
> > 31 is the smallest prime wich is equal to a multiple of his reversal (13)
> > +/- a
> >
> > prime smaller than him:
> >
> > 31 = 13 x 2 + 5
> >
> > 41 is the first with two solutions
> > 41 = 14 x 2 + 13
> > 41 = 14 x 5  - 29
> > 61 has four solutions :
> >
> > 61 = 16 x 2 + 29
> > 61 = 16 x 3 + 13
> > 61 = 16 x 4  -   3
> > 61 = 16 x 5  - 19
> >
> > with five and six solutions :
> >
> > 6421 = 1246 x 2 + 3929
> > 6421 = 1246 x 3 + 2683
> > 6421 = 1246 x 5 + 191
> > 6421 = 1246 x 8  - 3547
> > 6421 = 1246 x 9  - 4793
> >
> >
> > 8501 = 1058 x 6 + 2153
> > 8501 = 1058 x 8 + 37
> > 8501 = 1058 x 9  - 1021
> > 8501 = 1058 x 11  - 3137
> > 8501 = 1058 x 14  - 6311
> > 8501 = 1058 x 15  - 7369
> >
> > So the sequence begins 31, 41, ?, 61, 6421, 8501,
> > Is this of interest?
> > --
> > Claudio Meller
> >
> > _______________________________________________
> >
> > Seqfan Mailing list - http://list.seqfan.eu/
> >
>
> _______________________________________________
>
> Seqfan Mailing list - http://list.seqfan.eu/
>



-- 
Claudio Meller
http://grageasdefarmacia.blogspot.com
http://todoanagramas.blogspot.com/
http://simplementenumeros.blogspot.com/



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