# A027129 (b-file synthesized from sequence entry) 0 1 1 3 2 9 3 27 4 79 5 231 6 672 7 1951 8 5662 9 16439 10 47776 11 139025 12 405110 13 1182107 14 3454035 15 10105373 16 29600389 17 86800887 18 254797772 19 748646741 20 2201587214 21 6479524339 22 19084115993 23 56246912653 24 165882843095 25 489509315203