# A109251 (b-file synthesized from sequence entry)
0 0
1 1
2 22
3 247
4 2569
5 25556
6 250853
7 2444359
8 23727305
9 229924367
10 2227121996
11 21578747909
12 209214982913
13 2030133769624
14 19717814526785
15 191693417109381
16 1865380637252270
17 18168907486812690
18 177123437184971927
19 1728190923820610000