OFFSET
1,1
FORMULA
a(x) = 10^(x+1)*n+(10^x-1)*10+n+1. Output if a(x) is prime.
PROG
(PARI) n10np9(n, d) = { local(x, y, k); for(x=1, n, for(k=1, 8, y=10^(x+1)*k+(10^x-1)*10+k+1; if(isprime(y), print1(y", ")) ) ) }
CROSSREFS
KEYWORD
easy,nonn,base
AUTHOR
Cino Hilliard, Jul 11 2005
STATUS
approved