# A009640 (b-file synthesized from sequence entry)
0 0
1 1
2 -1
3 2
4 -10
5 46
6 -226
7 1532
8 -11880
9 96136
10 -882376
11 9179312
12 -102310000
13 1223945776
14 -15941391376
15 222827194592
16 -3303846357120
17 52077034777216
18 -871329939918976
19 15375474411183872
20 -285315305595562240
21 5562663216718387456
22 -113653337185088018176