# A047021 (b-file synthesized from sequence entry) 0 1 1 2 2 3 3 5 4 9 5 18 6 28 7 53 8 101 9 195 10 390 11 704 12 1371 13 2676 14 5253 15 10506 16 19840 17 39056 18 76968 19 152168 20 304336 21 586864 22 1161577 23 2300544 24 4565558 25 9131116 26 17813324 27 35369544 28 70256203 29 139745471 30 279490942 31 549138068 32 1092533184