OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
MATHEMATICA
Select[(Table[FromDigits/@Tuples[{1, 3, 9}, n], {n, 3, 5}]//Flatten), PrimeQ[#] && Min[ DigitCount[#, 10, {1, 3, 9}]]>0&] (* Harvey P. Dale, Apr 09 2017 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Rick L. Shepherd, Jun 01 2005
STATUS
approved