A134919 a(n)=floor(n^(5/3)).

1, 3, 6, 10, 14, 19, 25, 32, 38, 46, 54, 62, 71, 81, 91, 101, 112, 123, 135, 147, 159, 172, 186, 199, 213, 228, 243, 258, 273, 289, 305, 322, 339, 356, 374, 392, 410, 429, 448, 467, 487, 507, 527, 548, 569, 590, 612, 633, 656