# A028831 (b-file synthesized from sequence entry) 0 1 1 3 2 7 3 11 4 22 5 43 6 83 7 159 8 307 9 592 10 1141 11 2199 12 4239 13 8171 14 15750 15 30359 16 58519 17 112799 18 217427 19 419104 20 807849 21 1557179 22 3001559 23 5785691 24 11152278 25 21496707 26 41436235 27 79870911 28 153956131