# A001337 (b-file synthesized from sequence entry)
1 0
2 0
3 48
4 264
5 1680
6 11640
7 86352
8 673104
9 5424768
10 44828400
11 377810928
12 3235366752
13 28074857616
14 246353214240
15 2182457514960
16 19495053028800
17 175405981214592