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PROJECT EULER · #0840

Sum of Products

Statement only · SolvedOriginal problem ↗

A partition of n is a set of positive integers for which the sum equals n.
The partitions of 5 are:
{5},{1,4},{2,3},{1,1,3},{1,2,2},{1,1,1,2} and {1,1,1,1,1}.

Further we define the function D(p) as:
D(1)=1D(p)=1, for any prime pD(pq)=D(p)q+pD(q), for any positive integers p,q>1.

Now let {a1,a2,,ak} be a partition of n.
We assign to this particular partition the value:
P=j=1kD(aj).

G(n) is the sum of P for all partitions of n.
We can verify that G(10)=164.

We also define: S(N)=n=1NG(n). You are given S(10)=396.
Find S(5×104)mod999676999.

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