# A084859 (b-file synthesized from sequence entry) 0 1 1 4 2 16 3 62 4 232 5 842 6 2980 7 10334 8 35248 9 118610 10 394684 11 1301126 12 4255624 13 13825658 14 44657428 15 143521838 16 459230560 17 1463719586 18 4649308012 19 14722502870 20 46491507256 21 146447041994 22 460259735236 23 1443537130622