# A004138 (b-file synthesized from sequence entry) 1 1 2 2 3 3 4 8 5 13 6 24 7 37 8 66 9 107 10 186 11 303 12 516 13 849 14 1436 15 2377 16 3998 17 6639 18 11134 19 18531 20 31024 21 51701 22 86464 23 144205 24 241018 25 402163 26 671906 27 1121463 28 1873244 29 3127129 30 5222724 31 8719537 32 14561622 33 24312695 34 40600230 35 67790379 36 113201160 37 189016701 38 315627944 39 527024245 40 880037810 41 1469467515