# A150083 (b-file synthesized from sequence entry) 0 1 1 2 2 6 3 19 4 64 5 231 6 870 7 3381 8 13486 9 54572 10 224125 11 933929 12 3936544 13 16765384 14 71980646 15 311017381 16 1352436222 17 5916084672 18 26018810746 19 114980517626 20 510144652268 21 2271483627590 22 10149077070927 23 45495648807256 24 204569352272940 25 922360752757352 26 4168790748795270 27 18884057836684121