Partial sums of A072857.

Terms

a(0) =1a(1) =3a(2) =16a(3) =53a(4) =160a(5) =273a(6) =410a(7) =1423a(8) =2460a(9) =3539a(10) =4776a(11) =6143a(12) =7522a(13) =17601a(14) =27724a(15) =37860a(16) =47999a(17) =58236a(18) =68515a(19) =78882a(20) =89261a(21) =101640a(22) =115319a(23) =215598a(24) =315977a(25) =417214a(26) =519561a(27) =621940a(28) =725619a(29) =849098