%I
%S 1,11,13,17,25,31,35,43,65,71,83,95,97,101,125,127,137,151,155,157,
%T 161,163,167,187,197,203,205,211,217,221,223,227,233,235,245,251,257,
%U 263,265,271,283,317,331,335,337,341,353,355,373,385,391,401,427,433
%N Numbers n such that n concatenated with n + 6 is a prime.
%t Select[Range[1,501,2],PrimeQ[FromDigits[Join[IntegerDigits[#], IntegerDigits[ #+6]]]]&] (* _Harvey P. Dale_, Nov 17 2013 *)
%Y Cf. A032611.
%K nonn,base
%O 1,2
%A _Patrick De Geest_, May 15 1998
