OFFSET
1,1
COMMENTS
a(2)=137, 137 is prime, sum of digits 11 is prime, number of prime digits {3,7} 2 is prime, a(6)=223, 223 is prime, sum of digits 7 is prime, number of prime digits {2,2,3} 3 is prime, a (15)=359, 359 is prime, sum of digits 17 is prime, number of prime digits {3,5} 2 is prime, ...
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Jani Melik, May 19 2004
STATUS
approved