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

Terms

a(0) =1a(1) =16a(2) =62a(3) =219a(4) =405a(5) =1053a(6) =1523a(7) =2948a(8) =4407a(9) =7041a(10) =8703a(11) =15283a(12) =17949a(13) =24657a(14) =32685a(15) =44806a(16) =50536a(17) =70687a(18) =78573a(19) =105411a(20) =125879a(21) =149879a(22) =163565a(23) =222425a(24) =247476a(25) =286134a(26) =327634a(27) =396258a(28) =423084a(29) =532236