OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
MATHEMATICA
Select[Table[FromDigits[Join[IntegerDigits[n], IntegerDigits[n+7]]], {n, 1500}], PrimeQ] (* Harvey P. Dale, Sep 20 2016 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, May 15 1998
EXTENSIONS
Edited by Charles R Greathouse IV, Apr 28 2010
STATUS
approved