OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..600
MATHEMATICA
concatQ[n_]:=Module[{idn=IntegerDigits[n], len}, len=Length[idn]; EvenQ[ len]&&FromDigits[Take[idn, -len/2]]-FromDigits[Take[idn, len/2]]==5]; Select[Prime[Range[30000]], concatQ] (* Harvey P. Dale, Jul 30 2015 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, May 15 1998
EXTENSIONS
Edited by Charles R Greathouse IV, Apr 28 2010
STATUS
approved