# A013228 (b-file synthesized from sequence entry)
0 0
1 0
2 -1
3 1
4 -6
5 15
6 -105
7 390
8 -3500
9 15785
10 -188685
11 946350
12 -15864750
13 90057825
14 -2127610485
15 15254857800
16 -444774915000
17 4213468013625
18 -130378398500025
19 1538133793366950
20 -48054409884965250