Antidiagonal sums of A047920.

Terms

a(0) =1a(1) =1a(2) =2a(3) =7a(4) =29a(5) =141a(6) =832a(7) =5729a(8) =45217a(9) =402359a(10) =3985942a(11) =43500339a(12) =518515997a(13) =6702036193a(14) =93361811396