# A053481 (b-file synthesized from sequence entry)
0 2
1 11
2 76
3 654
4 6816
5 83880
6 1193760
7 19318320
8 350622720
9 7056927360
10 156031142400
11 3760042809600
12 98093779660800
13 2754553785984000
14 82841868639129600
15 2656672553703168000
16 90498598469959680000
17 3263440333591646208000