# A013275 (b-file synthesized from sequence entry)
0 0
1 0
2 -1
3 3
4 -6
5 15
6 -135
7 1260
8 -8820
9 65205
10 -722925
11 9043650
12 -101974950
13 1197971775
14 -17665522875
15 286053768000
16 -4408292889000
17 70284304715625
18 -1307027554457625
19 26160675737946750
20 -509941992726416250