# A001443 (b-file synthesized from sequence entry)
1 0
2 0
3 2
4 0
5 4
6 8
7 32
8 224
9 800
10 6660
11 27554
12 158680
13 1201626
14 9415980
15 76761968
16 672858900
17 6015305136
18 59514095596