# A009779 (b-file synthesized from sequence entry)
0 0
1 0
2 2
3 -6
4 14
5 -20
6 -36
7 336
8 720
9 -38016
10 524160
11 -5448960
12 50388480
13 -465903360
14 5010888960
15 -69353625600
16 1155961497600
17 -20593469030400
18 370356373094400
19 -6695551947571200
20 124010190839808000
21 -2408196729028608000