a(n) = Sum_{k=1..n} k*[ (n/k)*[ (n/k)*[ n/k ] ] ].

Terms

a(0) =1a(1) =10a(2) =32a(3) =87a(4) =161a(5) =309a(6) =462a(7) =737a(8) =1043a(9) =1477a(10) =1890a(11) =2610a(12) =3221a(13) =4079a(14) =5049a(15) =6235a(16) =7329a(17) =8958a(18) =10306a(19) =12317a(20) =14213a(21) =16370a(22) =18400a(23) =21586a(24) =24118a(25) =27216a(26) =30414a(27) =34325a(28) =37580a(29) =42520