# A020031 (b-file synthesized from sequence entry) 0 1 1 1 2 1 3 2 4 8 5 38 6 210 7 1380 8 10450 9 89574 10 857352 11 9063435 12 104876887 13 1318452295 14 17893281148 15 260730668151 16 4059948975491 17 67279154450986 18 1182190856781603 19 21954973054515490 20 429690186924088871