# A005549 (b-file synthesized from sequence entry) 3 1 4 12 5 54 6 188 7 636 8 2168 9 7556 10 26826 11 96724 12 353390 13 1305126 14 4864450 15 18272804 16 69103526 17 262871644 18 1005137688 19 3860909698 20 14890903690 21 57641869140 22 223864731680 23 872028568182 24 3406103773674 25 13337263822236