OFFSET
1,11
COMMENTS
It appears, as one would expect, that a(n) is asymptotically 1/4 n.
24 is the last n for which a(n) = 0.
FORMULA
a(n+1) = a(n) + floor(sqrt(n)) - A070039(n+1).
MATHEMATICA
Total/@Table[Mod[n, k], {n, 90}, {k, Sqrt[n]}] (* Harvey P. Dale, Nov 20 2013 *)
PROG
(PARI) a(n) = sum(k=2, sqrtint(n), n%k)
CROSSREFS
KEYWORD
nonn
AUTHOR
Franklin T. Adams-Watters, Apr 15 2010
STATUS
approved