Prime related questions

[xordan]

correction:

298765432123456789
The first prime  number ending with all the ciphers (9 to 1 to 9) in
palindromic order.
And :
1298765432123456789, 121298765432123456789
are in the same family.
Apologize the mistake.
Xordan
2007/6/3, xordan <xordan.tom at gmail.com>:

>
> Hello:
> You wrote:
> "Also, I was surprised to find that this seq wasn't already in the OEIS:
>  n such that 10^n + prime(n) is prime..."
>
> The sequence A125148, of which I am the  author, was modified by Klaus
> Brockhaus so that it could remain in OEIS, but originally that sequence was
> the following one:
>
> Prime Numbers  that p = (10^x*z)+Y  where Y  it is an odd number prime
> or  composite not divisible for 5  and x is equal or bigger that the
> quantity of ciphers of Y.
>
> Originally I deduced it for the  odd composites  , in way of demonstrating
> that for any combination of ciphers that they finish in 1,3,7, or 9 it is
> possible to find a prime number  adding a power of 10 equal or bigger than
> the  ciphers cuantity  of Y multiplied for  a number bigger than 0.
> Example:
> 9 are the first odd  composite number but 10^1*1+9=19
> 21 are the second odd  composite number (not divisible for 5) but
> 10^2*4+21=421
> 27 are the third add composite (not divisible for 5)  but 10^2*1+27=127.
> etc..
> In:
> http://primes.utm.edu/curios/page.php?number_id=6894&submitter=Xordan
> http://primes.utm.edu/curios/page.php?number_id=6983&submitter=Xordan
> you find the numbers:
> 28123456789
> The first prime number ending with all the ciphers (1 to 9) in order,
> and:
> 212345678987654321
> The first prime number ending with all the ciphers (1 to 9 to 1) in
> palindromic order.
>
>  These numbers were obtained form that algorithm, besides other
> curiosities that I have not remitted like:
> 11987654321234567879
> The first prime  number ending with all the ciphers (9 to 1 to 9) in
> palindromic order.
> Hope you find some resemblance...
> Greetings
>
> XORDAN
> Original in spanish, translated bysoftware
> .2007/6/3, Jason Earls <jcearls at cableone.net>:
> >
> > Dear Seqfans,
> >
> > I recently found these twin probable primes:
> >
> > 2357*2^7532+105525
> > 2357*2^7532+105527
> > (2271 digits)
> >
> > Anyone know of databases that keep track of these? They shouldn't be in
> > the
> > OEIS, should they?
> >
> > Also, I was surprised to find that this seq wasn't already in the OEIS:
> >
> > n such that 10^n + prime(n) is prime.
> > 2,4,27,63,756,899,
> >
> > I used PFGW to check up to 8000 and didn't find anymore.
> >
> > Worth submitting?
> >
> > Regards,
> > Jason
> > ======
> > Check out my novel, Red Zen:
> > http://tinyurl.com/2ylpml
> >
> >
> >
> >
>
>
> --
> xordan at hotmail.com
> xordan_co at yahoo.com
> xordan.tom at gmail.com




-- 
xordan at hotmail.com
xordan_co at yahoo.com
xordan.tom at gmail.com
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