# A064416 (b-file synthesized from sequence entry) 0 1 1 2 2 5 3 11 4 26 5 59 6 137 7 312 8 719 9 1651 10 3816 11 8757 12 20202 13 46440 14 106957 15 245989 16 566561 17 1303968 18 3002247 19 6910122 20 15909143