OFFSET
1,2
COMMENTS
a(26) = 9719 as both 989 and 899 are composite. This is the first genuine case in which the number of digits used is more than floor(n/9) + 1 (after single-digit composite even numbers 4 and 8).
EXAMPLE
a(7) = 7.
a(8) = 71 as 8 is not a prime.
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Sep 25 2003
EXTENSIONS
More terms from David Wasserman, Jul 25 2005
STATUS
approved