# A175716 (b-file synthesized from sequence entry)
0 0
1 1
2 6
3 27
4 120
5 560
6 2778
7 14665
8 82232
9 488403
10 3062980
11 20221520
12 140134404
13 1016698813
14 7703878042
15 60833235795
16 499592325152
17 4259301450652
18 37634032670886
19 344092369602461
20 3250925202629100