# A149030 (b-file synthesized from sequence entry) 0 1 1 1 2 3 3 10 4 33 5 124 6 478 7 1876 8 7653 9 31520 10 131923 11 560361 12 2397177 13 10362660 14 45122797 15 197619125 16 871134632 17 3857758844 18 17160398867 19 76658932408 20 343609269081 21 1545368262356 22 6971119129314 23 31529648390000 24 142971072421910 25 649780474978174 26 2959380924404418 27 13505223883964250