# A009731 (b-file synthesized from sequence entry)
0 0
1 1
2 0
3 5
4 -12
5 96
6 -480
7 3968
8 -29568
9 283840
10 -2759040
11 31139712
12 -369431040
13 4852567552
14 -67622790144
15 1018594276352
16 -16267048304640
17 277008597516288
18 -4982377179119616
19 94730142262034432
20 -1894021067538432000