# A009367 (b-file synthesized from sequence entry)
0 0
1 1
2 -1
3 2
4 -6
5 16
6 -72
7 496
8 -3248
9 24064
10 -208384
11 1908224
12 -19624704
13 227958784
14 -2800573440
15 36620830720
16 -519452284928
17 7865201852416
18 -126035093291008
19 2142236553248768
20 -38449509963399168
21 725477781101608960