The main diagonal of the triangular array A333284.

Terms

a(0) =5a(1) =37a(2) =405a(3) =2225a(4) =11641a(5) =35677a(6) =114409a(7) =295701a(8) =718469a(9) =1475709a(10) =3093025a(11) =5771929a(12) =10895273a(13) =18785841a(14) =31414269a(15) =50274501a(16) =81288641a(17) =124066161a(18) =190860537a(19) =282399889a(20) =411505049a(21) =580614301a(22) =824814797a(23) =1138709849a(24) =1570665877a(25) =2115178249a(26) =2833746309a(27) =3732420861a(28) =4937226173