# A013203 (b-file synthesized from sequence entry)
0 0
1 1
2 -2
3 6
4 -20
5 128
6 -920
7 7784
8 -75616
9 863168
10 -10897792
11 153777536
12 -2374754560
13 40156766336
14 -733521418240
15 14452100967680
16 -304697481490432
17 6857570007949312
18 -163883915313774592