# A080668 (b-file synthesized from sequence entry)
1 2
2 10
3 33
4 88
5 245
6 936
7 5383
8 40832
9 363609
10 3629800
11 39918131
12 479003328
13 6227022997
14 87178293944
15 1307674371375
16 20922789892096
17 355687428100913
18 6402373705733832
19 121645100408838859
20 2432902008176648000