Fourth row of A113439.

Terms

a(0) =1a(1) =5a(2) =23a(3) =101a(4) =436a(5) =1871a(6) =8014a(7) =34309a(8) =146868a(9) =628708a(10) =2691401a(11) =11521603a(12) =49323052a(13) =211148530a(14) =903912916a(15) =3869592721a(16) =16565477544a(17) =70915744968a(18) =303585747088