Row sums of the table A047916.

Terms

a(0) =1a(1) =4a(2) =12a(3) =40a(4) =140a(5) =816a(6) =5082a(7) =40800a(8) =363258a(9) =3632880a(10) =39916910a(11) =479052528a(12) =6227020956a(13) =87178936992