OFFSET
1,2
COMMENTS
a(7) > 29*10^9; a(8) = 11978.
a(n) > 10^10 for n from 9 to 11. a(12) = 120998. [From Donovan Johnson, Oct 24 2009]
EXAMPLE
a(4) = 111 as 111, 115, 119 and 123 all are of the prime signature p*q.
CROSSREFS
KEYWORD
nonn,hard
AUTHOR
Amarnath Murthy, Sep 02 2003
EXTENSIONS
Edited and extended by David Wasserman, Jan 08 2006
a(7) from Donovan Johnson, Oct 24 2009
STATUS
approved