OFFSET
1,1
EXAMPLE
The number 910109 is prime and corresponds to n=10.
The number 9101310139 is prime and corresponds to n=1013.
MATHEMATICA
fQ[n_] := Block[{id = IntegerDigits[n]}, PrimeQ[ FromDigits[ Join[{9}, id, id, {9}]]]]; Select[ Range[1288], fQ[ # ] &] (* Robert G. Wilson v, Jan 14 2004 *)
CROSSREFS
KEYWORD
easy,nonn,base
AUTHOR
Mark Hudson (mrmarkhudson(AT)hotmail.com), Jan 13 2005
EXTENSIONS
More terms from Robert G. Wilson v, Jan 14 2005
STATUS
approved