OFFSET
1,1
COMMENTS
Chances are these numbers are infinite since PIPs are infinite.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..14683 (terms below 10^11)
Albert Frank and Philippe Jacqueroux, International Contest, 2001. Item 12.
EXAMPLE
59 is prime, the 59th prime is 277, and 2 and 7 are primes.
MATHEMATICA
Select[Flatten[Table[FromDigits /@ Tuples[Prime[Range[4]], k], {k, 1, 6}]], PrimeQ[#] && PrimeQ[PrimePi[#]] &] (* Amiram Eldar, Jul 08 2024 *)
PROG
(PARI) pip(n) = { for(x=1, n, flag=1; y=prime(prime(x)); y2=y; for(j=1, length(Str(y)), r = y%10; if(!isprime(r), flag=0); y = floor(y/10); ); if(flag, print1(y2", ")); ) }
CROSSREFS
KEYWORD
easy,nonn,base
AUTHOR
Cino Hilliard, Oct 21 2003
EXTENSIONS
Offset corrected by Amiram Eldar, Jul 08 2024
STATUS
approved