sequence of Zak Seidov needs extending

[Alex Healy]

I also threw together a quick program for this, and can't seem to find any
other terms less than (2.5)*10^12.  (That's just where my program was when I
woke up this morning.)

For what it's worth, the first four terms of the same sequence in binary
(i.e. requiring that the primes be palindromic in base two) are:

5, 17, 127, 296713

and there don't seem to be any others less than 10^11.

Alex 

> -----Original Message-----
> From: Jud McCranie [mailto:j.mccranie at adelphia.net] 
> Sent: Thursday, February 03, 2005 12:52 AM
> To: njas at research.att.com
> Cc: seqfan at ext.jussieu.fr; zakseidov at yahoo.com
> Subject: Re: sequence of Zak Seidov needs extending
> 
> At 11:00 PM 2/2/2005, N. J. A. Sloane wrote:
> >Dear Seqfans, Zak submitted this, but I can't use it without 
> at least 
> >one more term. Can anyone extend it?
> >
> >
> >%I A103359
> >%S A103359 3,5,11
> >%N A103359 Prime palindromic n such that pi(n) [A000720] is 
> prime palindromic.
> >%C A103359 No further terms with n less than 3000000. 
> Palindromic pi(n) 
> >of palindromic n A103357,A103358.
> >%e A103359 pi(3)=2, pi(5)=3,pi(11)=5
> >%Y A103359 Cf. A103357, A103358.
> >%O A103359 0,1
> >%K A103359 more,nonn,base,bref
> >%A A103359 Zak Seidov (zakseidov(AT)yahoo.com), Feb 02 2005
> 
> My quick and dirty program doesn't find any more terms < 
> 10^10.  Tomorrow I can modify it to go higher.
> 
> More terms are going to be hard to find.
> 
> pi(143787341) =  8114118, a palindrome, but not prime - is 
> the closest I've found. (143787341 is a palindromic prime).
> 
> You might have to relax the condition that pi(n) be a prime, 
> and just require it to be palindromic, while n is a palindromic prime.
> 
>