# A227293 (b-file synthesized from sequence entry)
0 1
1 2
2 -2
3 4
4 -2
5 12
6 -36
7 104
8 -330
9 1068
10 -3356
11 10808
12 -35156
13 115192
14 -380744
15 1267152
16 -4242778
17 14285644
18 -48336684
19 164272984
20 -560515836
21 1919455464
22 -6594719992
23 22725877680
24 -78531331524
25 272062125048
26 -944738639640
27 3287748182064
28 -11464667424744
29 40053463412080
30 -140178051713680
31 491396601445280