# A026389 (b-file synthesized from sequence entry) 2 1 3 8 4 49 5 272 6 1440 7 7428 8 37730 9 189808 10 948909 11 4724160 12 23453001 13 116207424 14 575036475 15 2842936320 16 14046869575 17 69378730880 18 342590699955 19 1691519468760 20 8351553940355 21 41235710124400 22 203617691311370 23 1005560117623204