Partial sums of A051879.

Terms

a(0) =1a(1) =15a(2) =84a(3) =308a(4) =882a(5) =2142a(6) =4620a(7) =9108a(8) =16731a(9) =29029a(10) =48048a(11) =76440a(12) =117572a(13) =175644a(14) =255816a(15) =364344a(16) =508725a(17) =697851a(18) =942172a(19) =1253868a(20) =1647030a(21) =2137850a(22) =2744820a(23) =3488940a(24) =4393935a(25) =5486481a(26) =6796440a(27) =8357104a(28) =10205448a(29) =12382392