# A020131 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 4 4 14 5 65 6 370 7 2496 8 19339 9 169215 10 1649844 11 17735823 12 208395916 13 2657047924 14 36534408954 15 538882532061 16 8487399879955 17 142163947989233 18 2523410076808877 19 47313938940166439 20 934450294068287158