# A230554 (b-file synthesized from sequence entry)
0 1
1 1
2 2
3 4
4 9
5 21
6 51
7 126
8 321
9 820
10 2160
11 5654
12 15272
13 40758
14 112280
15 304471
16 852164
17 2341980
18 6640755
19 18460066
20 52915999