# A261193 (b-file synthesized from sequence entry)
0 -1
1 -1
2 0
3 4
4 22
5 118
6 718
7 5038
8 40318
9 362878
10 3628798
11 39916798
12 479001598
13 6227020798
14 87178291198
15 1307674367998
16 20922789887998
17 355687428095998
18 6402373705727998
19 121645100408831998
20 2432902008176639998
21 51090942171709439998
22 1124000727777607679998