# A005580 (b-file synthesized from sequence entry)
2 3
3 8
4 21
5 54
6 141
7 372
8 995
9 2697
10 7397
11 20502
12 57347
13 161658
14 458788
15 1309626
16 3757383
17 10828011
18 31326513
19 90945528