Partial sums of A053308.

Terms

a(0) =1a(1) =10a(2) =56a(3) =231a(4) =782a(5) =2300a(6) =6085a(7) =14820a(8) =33775a(9) =72905a(10) =150438a(11) =298925a(12) =575333a(13) =1077748a(14) =1972851a(15) =3540913a(16) =6249235a(17) =10871723a(18) =18683233a(19) =31775031a(20) =53566369a(21) =89633545a(22) =149052839a(23) =246575109a(24) =406146248a(25) =666605513a(26) =1090907965