# A274520 (b-file synthesized from sequence entry)
0 0
1 2
2 4
3 20
4 64
5 248
6 880
7 3248
8 11776
9 43040
10 156736
11 571712
12 2083840
13 7597952
14 27698944
15 100985600
16 368164864
17 1342243328
18 4893475840
19 17840411648
20 65041678336
21 237125826560
22 864501723136
23 3151758405632
24 11490527150080
25 41891604733952
26 152726372368384