# A049117 (b-file synthesized from sequence entry)
0 3
1 7
2 19
3 47
4 163
5 487
6 1307
7 2879
8 19683
9 39367
10 177147
11 531441
12 1594323
13 4782969
14 14348907
15 43046721
16 86093443
17 258280327
18 688747547
19 3486784401
20 10460353203