# A338987 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 6 4 24 5 108 6 596 7 3674 8 26068 9 202470 10 1753884 11 16435754 12 168174596 13 1842418704 14 21757407158 15 272771715272 16 3649515044178 17 51532670206504 18 770442883634326 19 12093451621846094 20 199856952123506304 21 3452120352032161404 22 62471981051497913826 23 1177664861561125869100 24 23163177237781937250558