OFFSET
1,2
COMMENTS
a(11) is the first semiprime in the sequence. What is the next? After a(2) = 5, is there another prime?
FORMULA
EXAMPLE
a(2) = 5 because 5 + a(1) = 2 * 3.
a(3) = 380 because 380 + a(2) = 5 * 7 * 11.
a(4) = 96197 because 96197 + a(3) = 13 * 17 * 19 * 23 (note that 96197 is coincidentally the 3-brilliant 19 * 61 * 83).
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, Nov 22 2004
EXTENSIONS
Offset and formula corrected by Giovanni Resta, Jun 17 2016
STATUS
approved