OFFSET
4,1
LINKS
EXAMPLE
a(1)=2047 because 2047 is the smallest 4-digit strong pseudoprime to base 2.
CROSSREFS
KEYWORD
hard,base,nonn
AUTHOR
Shyam Sunder Gupta, Feb 13 2002
EXTENSIONS
Edited by Charles R Greathouse IV, Nov 01 2009
a(17)-a(20) from Charles R Greathouse IV, Mar 14 2011
STATUS
approved