OFFSET
1,2
FORMULA
EXAMPLE
The smallest number not dividing 1 is 2, so a(2) = 1+2 = 3.
The numbers not dividing 3 are 2, 4, 5, 6, ..., so a(3) = 3+5 = 8.
The numbers not dividing 8 are 3, 5, 6, 7, 9, 10, 11, 12, ..., so a(4) = 8+12 = 20.
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric Angelini, Jun 25 2008
EXTENSIONS
More terms from Hans Havermann, Jun 25 2008
STATUS
approved