OFFSET
1,1
COMMENTS
a(16)=0 since the concatenation of 53 with itself, followed by a 9, is always composite. a(36), if it exists, has more than 12000 digits. - Giovanni Resta, Apr 07 2006
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Mar 28 2004
EXTENSIONS
More terms from Sam Alexander, Jan 09 2005
More terms from Giovanni Resta, Apr 07 2006
STATUS
approved