OFFSET
1,2
FORMULA
Count odd composites 1 mod 4 less than 10^n
For n>1, a(n) = 25*10^(n-2) - 1 - A091098(n). - Max Alekseyev, May 30 2007
EXAMPLE
Below 10^2 there are 13 odd composites so a(2)=13
CROSSREFS
KEYWORD
nonn
AUTHOR
Enoch Haga, Mar 24 2004
EXTENSIONS
More terms from Max Alekseyev, May 30 2007
Extended by Max Alekseyev, Oct 13 2009
STATUS
approved