# A049147 (b-file synthesized from sequence entry) 1 1 2 1 3 0 4 0 5 2 6 2 7 4 8 27 9 78 10 222 11 816 12 2736 13 8784 14 29704 15 100408 16 334889 17 1128036 18 3819368 19 12912484 20 43771606 21 148863396 22 506943540 23 1729339848 24 5911769970 25 20242876176 26 69422168880 27 238465602096 28 820352668488 29 2826032713656