The rightmost column of triangle A094280.

Terms

a(0) =1a(1) =3a(2) =6a(3) =21a(4) =44a(5) =100a(6) =227a(7) =517a(8) =1148a(9) =2469a(10) =5205a(11) =10794a(12) =22110a(13) =44910a(14) =90700a(15) =182535a(16) =366488a(17) =734713a(18) =1471527a(19) =2945567a(20) =5894110a(21) =11791702a(22) =23587471a(23) =47179664a(24) =94364748a(25) =188735680a(26) =377478377a(27) =754964676a(28) =1509938254