# A006604 (b-file synthesized from sequence entry)
0 1
1 1
2 4
3 13
4 53
5 228
6 1037
7 4885
8 23640
9 116793
10 586633
11 2986616
12 15377097
13 79927913
14 418852716
15 2210503285
16 11738292397
17 62673984492
18 336260313765
19 1811960161517
20 9802082905840
21 53213718977777
22 289817858570513
23 1583076422786096
24 8670574105626961