# A047046 (b-file synthesized from sequence entry) 0 1 1 2 2 5 3 14 4 42 5 146 6 513 7 1814 8 6457 9 23852 10 88822 11 331756 12 1241569 13 4704536 14 17919729 15 68426280 16 261659138 17 1005583928 18 3876858984 19 14975423376 20 57918225459 21 224542599510 22 872234912198 23 3393031324338 24 13212674724177