# A006816 (b-file synthesized from sequence entry) 1 1 2 6 3 29 4 108 5 393 6 1298 7 4271 8 13312 9 41469 10 125042 11 376747 12 1111144 13 3274475 14 9505054 15 27573041 16 79086964 17 226727667 18 644301026 19 1830188555 20 5162408200 21 14556754485 22 40811281170