# A002495 (b-file synthesized from sequence entry)
0 1
1 0
2 2
3 2676
4 101118
5 1644784
6 16044996
7 110148864
8 584716268
9 2549726784
10 9515920164
11 31314134428
12 92917720104
13 252775518960
14 638328487880
15 1511740834560
16 3387163064214
17 7228599229760
18 14768913424614
19 29023937463900
20 55107648867544
21 101434033397472