# A018171 (b-file synthesized from sequence entry)
0 1
1 1
2 3
3 6
4 10
5 20
6 36
7 66
8 120
9 219
10 400
11 728
12 1325
13 2413
14 4394
15 8000
16 14564
17 26515
18 48273
19 87884
20 160000
21 291290
22 530312
23 965468
24 1757696
25 3200000
26 5825805
27 10606252
28 19309364
29 35153937
30 64000000
31 116516108