# A090032 (b-file synthesized from sequence entry) 0 1 1 2 2 4 3 10 4 26 5 66 6 171 7 440 8 1112 9 2786 10 6820 11 16720 12 41106 13 100856 14 245793 15 597030 16 1441292 17 3469486 18 8304526 19 19832076 20 47110238 21 111669014