OFFSET
1,9
EXAMPLE
a(20) = #{17+3, 11+9, 11+5+3+1} = 3;
a(21) = #{21, 17+3+1, 11+9+1} = 3;
a(22) = #{21+1, 17+5} = 2.
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jun 21 2008
STATUS
approved