OFFSET
1,1
EXAMPLE
n=2,x=3. a(x,n) = 2*10^3+2+1 = 2003 prime.
MATHEMATICA
Select[Union[Flatten[Table[n*10^x+n+1, {n, 8}, {x, 0, 20}]]], PrimeQ] (* Harvey P. Dale, Jul 09 2020 *)
PROG
(PARI) n10np1(n) = { local(x, y, k); for(x=0, n, for(k=1, 8, y=10^x*k+k+1; if(isprime(y), print1(y", ")) ) ) }
CROSSREFS
KEYWORD
nonn
AUTHOR
Cino Hilliard, Jul 10, 2005
STATUS
approved