# A187986 (b-file synthesized from sequence entry) 1 0 2 7 3 15 4 60 5 222 6 746 7 2742 8 9689 9 34588 10 124062 11 443469 12 1591177 13 5710783 14 20514746 15 73779819 16 265523140 17 956384656 18 3447285428 19 12433999199 20 44877035870 21 162066465738 22 585603996081 23 2117103447068 24 7657611562951 25 27710598382843 26 100320181906860 27 363337451934873 28 1316442508560564