# A037520 (b-file synthesized from sequence entry)
1 2
2 7
3 21
4 65
5 196
6 588
7 1766
8 5299
9 15897
10 47693
11 143080
12 429240
13 1287722
14 3863167
15 11589501
16 34768505
17 104305516
18 312916548
19 938749646
20 2816248939
21 8448746817
22 25346240453
23 76038721360
24 228116164080
25 684348492242