# A027909 (b-file synthesized from sequence entry)
0 1
1 4
2 21
3 112
4 615
5 3432
6 19383
7 110448
8 633726
9 3656360
10 21191555
11 123286440
12 719539015
13 4210967880
14 24702429825
15 145210795200
16 855172338570
17 5044470461352
18 29799593861974
19 176268499363840
20 1043889366927771
21 6188748520285584
22 36726461258947569
23 218146172715259488
24 1296812014083995850