Sum{T(n,k): k=0,1,...,n}, array T as in A054098.

Terms

a(0) =1a(1) =3a(2) =6a(3) =14a(4) =44a(5) =178a(6) =892a(7) =5354a(8) =37480a(9) =299842a(10) =2698580a(11) =26985802a(12) =296843824a(13) =3562125890a(14) =46307636572a(15) =648306912010