a(n) = Sum_{k=0..n} floor(k^(1/3)).

Terms

a(0) =0a(1) =1a(2) =2a(3) =3a(4) =4a(5) =5a(6) =6a(7) =7a(8) =9a(9) =11a(10) =13a(11) =15a(12) =17a(13) =19a(14) =21a(15) =23a(16) =25a(17) =27a(18) =29a(19) =31a(20) =33a(21) =35a(22) =37a(23) =39a(24) =41a(25) =43a(26) =45a(27) =48a(28) =51a(29) =54