a(n) = floor( Sum_{1 <= i < j <= n} ((sqrt(j)-sqrt(i))^3) ).

Terms

a(0) =0a(1) =0a(2) =1a(3) =4a(4) =8a(5) =16a(6) =27a(7) =43a(8) =64a(9) =92a(10) =128a(11) =172a(12) =227a(13) =294a(14) =373a(15) =467a(16) =576a(17) =703a(18) =849a(19) =1015a(20) =1203a(21) =1414a(22) =1652a(23) =1916a(24) =2209a(25) =2533a(26) =2890a(27) =3282a(28) =3710a(29) =4177