a(n) = Product_{k=0..n} binomial(3*k,k).A268196a(n) = Product_{k=0..n} binomial(3*k,k).Terms a(0) =1a(1) =3a(2) =45a(3) =3780a(4) =1871100a(5) =5618913300External referencesoeis: A268196