# A006172 (b-file synthesized from sequence entry) 0 4 1 2 2 9 3 10 4 42 5 79 6 252 7 582 8 1645 9 4106 10 11070 11 28459 12 75348 13 195898 14 515073 15 1344906 16 3526786 17 9223895 18 24163596 19 63236638 20 165595269 21 433469962 22 1134942774 23 2971150995 24 7778845732 25 20364843314 26 53316562617 27 139583423242 28 365436006810 29 956720876191 30 2504732642460