Column 3 of triangle A354650: a(n) = A354650(n,3), for n >= 1.

Terms

a(0) =1a(1) =30a(2) =340a(3) =2530a(4) =14595a(5) =70737a(6) =301070a(7) =1157820a(8) =4100785a(9) =13563010a(10) =42321840a(11) =125586440a(12) =356621070a(13) =973989030a(14) =2569116330a(15) =6567458520a(16) =16317741975a(17) =39504992395a(18) =93390535840a(19) =215983566780a(20) =489454806785