OFFSET
1,2
EXAMPLE
a(4)=14 because 41 is prime. a(8000)=47712 because 71 is prime.
MATHEMATICA
Select[Range[2, 200], PrimeQ[FromDigits[{Max[IntegerDigits[#]], Min[ IntegerDigits[#]]}]]&] (* Harvey P. Dale, Mar 29 2015 *)
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Jason Earls, Jun 25 2003
EXTENSIONS
Missing a(1)=1 inserted by Sean A. Irvine, Oct 13 2019
STATUS
approved