# A072470 (b-file synthesized from sequence entry) 0 0 1 9 2 16 3 144 4 7056 5 17424 6 151880976 7 3370896 8 11141224704 9 65067847056 10 39037856400 11 107295207555600 12 189756686048400 13 3749779657193648400 14 2631616745340978864144 15 15179712895673097530256