# A255469 (b-file synthesized from sequence entry) 0 1 1 6 2 20 3 84 4 296 5 1124 6 4056 7 15100 8 55288 9 204740 10 753336 11 2782588 12 10252952 13 37831684 14 139470616 15 514443580 16 1896954168 17 6996160196 18 25799583352 19 95147186940 20 350881763288 21 1294007162500 22 4772059430872 23 17598637988284 24 64900766401656 25 239343741625668 26 882659972822840 27 3255107458681212 28 12004301666699032