OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..10000
EXAMPLE
139 is a member as 31393 is also a prime.
MATHEMATICA
Select[ Range[1000], PrimeQ[ # ] && PrimeQ[ FromDigits[ Insert[ IntegerDigits[ # ], 3, {{1}, {-1}}]]] &]
Select[Prime[Range[200]], PrimeQ[FromDigits[Join[{3}, IntegerDigits[#], {3}]]]&] (* Harvey P. Dale, Oct 24 2011 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Amarnath Murthy, Apr 06 2002
EXTENSIONS
Edited and extended by Robert G. Wilson v, May 03 2002
STATUS
approved