OFFSET
1,7
COMMENTS
It appears that the indices of the zeros in the sequence are in A018253. - Omar E. Pol, Oct 22 2013
EXAMPLE
n=15: sequence of D1 = {floor(15/j)} = {15,7,5,3,3,2,2,1,1,1,1,1,1,1,1}, Union(D1) = {15,7,5,3,2,1} = divisors(15) and {7,2}, a(15)=2 the number of terms beyond divisors.
MATHEMATICA
Table[Length[Union[Table[Floor[w/j], {j, 1, w}]]] -DivisorSigma[0, w], {w, 1, 128}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Nov 27 2002
STATUS
approved