# A124497 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 4 4 9 5 20 6 48 7 116 8 288 9 724 10 1849 11 4768 12 12423 13 32628 14 86342 15 229952 16 616042 17 1659012 18 4489101 19 12199521 20 33284546 21 91140797 22 250396629 23 690043032 24 1907022197 25 5284167884 26 14677681554 27 40862469713 28 114001697975