A141801 For n>=2, a(n) = sum{k=1 to n} (largest prime dividing (n*k)). a(1)=0.

0, 4, 9, 9, 25, 20, 49, 26, 33, 52, 121, 52, 169, 108, 93, 75, 289, 100, 361, 144, 179, 258, 529, 168, 195, 358, 189, 254, 841, 254, 961, 258, 431, 612, 363, 302, 1369, 766, 595, 404, 1681, 494, 1849, 656, 511, 1124, 2209, 556, 639, 598, 1009, 870, 2809, 654, 875