OFFSET
1,6
COMMENTS
See A064990.
FORMULA
s(n)=s([(n+2)/3])+s([(n+1)/3])+[n/3]-s([n/3]), where s(0)=0, s(1)=0.
MATHEMATICA
(See A064990.)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Apr 25 2011
STATUS
approved