# A231331 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 3 4 6 5 10 6 20 7 35 8 74 9 130 10 258 11 473 12 1007 13 1830 14 3912 15 7093 16 15233 17 27831 18 60458 19 109555 20 239039 21 433654 22 946849 23 1709524 24 3746021 25 6750928