Row sums and second diagonal of A046934.

Terms

a(0) =1a(1) =1a(2) =4a(3) =15a(4) =61a(5) =272a(6) =1317a(7) =6865a(8) =38278a(9) =227093a(10) =1426921a(11) =9457918a(12) =65898275a(13) =481177881a(14) =3672102116a(15) =29218285875a(16) =241873478425