Partial sums of A051946.

Terms

a(0) =1a(1) =12a(2) =68a(3) =264a(4) =810a(5) =2112a(6) =4884a(7) =10296a(8) =20163a(9) =37180a(10) =65208a(11) =109616a(12) =177684a(13) =279072a(14) =426360a(15) =635664a(16) =927333a(17) =1326732a(18) =1865116a(19) =2580600a(20) =3519230a(21) =4736160a(22) =6296940a(23) =8278920a(24) =10772775a(25) =13884156a(26) =17735472a(27) =22467808a(28) =28242984a(29) =35245760