# A020038 (b-file synthesized from sequence entry) 0 1 1 1 2 1 3 2 4 9 5 41 6 231 7 1528 8 11610 9 99850 10 958562 11 10160756 12 117864768 13 1485096081 14 20197306708 15 294880677942 16 4600138575888 17 76362300359740 18 1343976486331426 19 24997962645764522 20 489960067856984638