OFFSET
1,1
COMMENTS
The n-th colossally abundant number - 1 is prime for n = 2, 3, 4, 6, 8, 9, 11, 34, 36, 43, 73, 81, 86, 115.
EXAMPLE
A004490(11) = 1441440, and 1441440 - 1 = 1441439 is prime.
CROSSREFS
KEYWORD
nonn
AUTHOR
Jonathan Vos Post, Jan 31 2011
EXTENSIONS
a(11) from Charles R Greathouse IV, Oct 09 2011
STATUS
approved