# A005173 (b-file synthesized from sequence entry)
1 0
2 1
3 12
4 61
5 240
6 841
7 2772
8 8821
9 27480
10 84481
11 257532
12 780781
13 2358720
14 7108921
15 21392292
16 64307941
17 193185960
18 580082161
19 1741295052
20 5225982301
21 15682141200
22 47054812201
23 141181213812
24 423577195861
25 1270798696440