a(n) = 2^n * (3n)! / (2n+1)!.A014298a(n) = 2^n * (3n)! / (2n+1)!.Terms a(0) =1a(1) =2a(2) =24a(3) =576a(4) =21120a(5) =1048320a(6) =65802240a(7) =5000970240a(8) =446557224960External referencesoeis: A014298