Partial sums of floor(n^2/3) (A000212).

Terms

a(0) =0a(1) =0a(2) =1a(3) =4a(4) =9a(5) =17a(6) =29a(7) =45a(8) =66a(9) =93a(10) =126a(11) =166a(12) =214a(13) =270a(14) =335a(15) =410a(16) =495a(17) =591a(18) =699a(19) =819a(20) =952a(21) =1099a(22) =1260a(23) =1436a(24) =1628a(25) =1836a(26) =2061a(27) =2304a(28) =2565a(29) =2845