# A004048 (b-file synthesized from sequence entry)
0 1
1 0
2 756
3 8736
4 44226
5 187488
6 531468
7 1314144
8 3097332
9 6141408
10 10968048
11 21258720
12 34038186
13 53778816
14 88943400
15 131804064
16 184024386
17 289650816
18 387420516
19 524343456
20 756139104
21 992308512