# A149866 (b-file synthesized from sequence entry) 0 1 1 2 2 5 3 13 4 40 5 134 6 467 7 1671 8 6172 9 23436 10 90370 11 354271 12 1410448 13 5681881 14 23111260 15 94915721 16 393246863 17 1640456796 18 6888518741 19 29110220069 20 123682094892 21 528032933464 22 2264948231740 23 9757427695261 24 42194050729094 25 183120618953859 26 797497306584136 27 3483922404178219 28 15263691795321215