# A018100 (b-file synthesized from sequence entry) 0 1 1 2 2 4 3 9 4 19 5 40 6 83 7 173 8 361 9 754 10 1574 11 3285 12 6859 13 14320 14 29898 15 62420 16 130321 17 272084 18 568056 19 1185986 20 2476099 21 5169594 22 10793065 23 22533736 24 47045881 25 98222279 26 205068241 27 428140988 28 893871739