# A022867 (b-file synthesized from sequence entry) 1 2 2 2 3 2 4 3 5 5 6 10 7 21 8 45 9 99 10 219 11 485 12 1076 13 2389 14 5306 15 11786 16 26182 17 58164 18 129215 19 287062 20 637734 21 1416785 22 3147520 23 6992512 24 15534524 25 34511410 26 76670354 27 170330428 28 378405125 29 840662707 30 1867611566 31 4149075406