a(n) = Sum_{k=0..n} p(k) where the p(k) are the partial sums of row n of A365676.

Terms

a(0) =1a(1) =1a(2) =4a(3) =8a(4) =18a(5) =30a(6) =58a(7) =90a(8) =153a(9) =233a(10) =365a(11) =533a(12) =806a(13) =1142a(14) =1652a(15) =2308a(16) =3243a(17) =4431a(18) =6103a(19) =8203a(20) =11080a(21) =14710a(22) =19540a(23) =25612a(24) =33612a(25) =43570a(26) =56476a(27) =72548a(28) =93080a(29) =118490