a(n) = Sum_{k=1..prime(n)-1} floor(k^3/prime(n)).

Terms

a(0) =0a(1) =2a(2) =18a(3) =60a(4) =270a(5) =462a(6) =1080a(7) =1530a(8) =2772a(9) =5670a(10) =6960a(11) =11970a(12) =16380a(13) =18942a(14) =24840a(15) =35802a(16) =49590a(17) =54870a(18) =72930a(19) =86940a(20) =94572a(21) =120120a(22) =139482a(23) =172260a(24) =223440a(25) =252450a(26) =267852a(27) =300510a(28) =317790a(29) =354312