# A297197 (b-file synthesized from sequence entry) 0 1 1 2 2 4 3 10 4 34 5 146 6 752 7 4520 8 31062 9 240188 10 2063846 11 19508770 12 201184666 13 2247704104 14 27044622168 15 348654862510 16 4794539357488 17 70054014476102 18 1083796147054274 19 17698938549553490 20 304247125951777284