# A005947 (b-file synthesized from sequence entry)
0 0
1 3
2 16
3 75
4 356
5 1770
6 9306
7 51821
8 305232
9 1897227
10 12411650
11 85234864
12 612903324
13 4604004691
14 36050248752
15 293659886235
16 2483993559376
17 21781908622738
18 197701336871190
19 1854695911048053
20 17960309481562600
21 179309794875495795